Acceptance by her service technical control and delivery to the warehouse finished products, which is measured in days, hours.

The production cycle has two stages:

Time of the production process;
break times in the production process.

The time of the production process, which is called the technological cycle, or working period, includes:

Time for preparatory and final operations;
time for technological operations;
time for the course of natural technological processes;
time for transportation in the production process;
time for technical control.

The time of interruptions in the production process is the time during which no impact is made on the object of labor and there is no change in its qualitative characteristics, but the product is not yet finished and the production process is not completed.

Break times in the production process include:

Time of interoperative decubitus;
time between shifts.

The preparatory and final time is spent by the worker (or team) on preparing himself and his workplace for the performance of the production task, as well as on all actions to complete it. It includes the time to obtain a work order, material, special tools and fixtures, equipment adjustment, etc.

The time of technological operations is the time during which a direct impact on the object of labor is carried out either by the worker himself or by machines and mechanisms under his control.

The time of natural technological processes is the time during which the object of labor changes its characteristics without the direct influence of man and technology (air drying of a painted product or cooling of a heated product, growth and maturation of plants, fermentation of certain products, etc.).

The time for technical control and the time for transportation in the production process constitute the maintenance time, which includes:

Quality control of product processing;
control of operating modes of machines and equipment, their adjustment, minor repairs;
transportation of blanks, materials, acceptance and cleaning of processed products.

Interoperational (intra-shift) breaks are divided into:

Partion breaks - take place when parts are processed in batches: each part or assembly, entering the workplace as part of a batch, lies twice - before and after processing, until the entire batch passes through this operation;
wait breaks - due to inconsistency (non-synchronism) in the duration of adjacent operations of the technological process and occur when the previous operation ends before it is released workplace to perform the next operation;
picking breaks - occur in cases where parts and assemblies lie due to the unfinished production of other parts included in one set. Breaks between shifts are determined by the mode of operation (the number and duration of shifts) and include breaks between work shifts, weekends and holidays, lunch breaks.

Inter-operational and inter-shift breaks are regulated breaks.

Unscheduled breaks are associated with downtime of equipment and workers for various organizational and technical reasons not provided for by the operating mode (lack of raw materials, equipment breakdown, absenteeism of workers, etc.), and are not included in the production cycle.

Production cycle time

Know duration production cycle necessary to create production program, to determine the timing of launching into production of specific types of products for a given or specified in the contract period for the release of the same products. The duration of the production cycle is used when calculating the value of work in progress. Reducing the duration of the production cycle is of great economic importance. The smaller it is, the greater the volume of production, the higher the efficiency of the use of fixed assets, the less the need for working capital invested in work in progress, ceteris paribus.

Considering the structure of the production cycle, there are 3 components:

1. operation execution time (main and auxiliary);
2. time of natural processes;
3. break time.

The execution time of the main operations that are aimed at changing the geometric dimensions, shape, composition of objects of labor form a technological cycle, which is the basis of the production cycle (obtaining a workpiece, its processing, assembly and welding).

Auxiliary operations are associated with the control of technological processes, and with the transportation of objects of labor in the process of processing. Natural processes do not require human participation, but require time (aging, drying). In the structure of a simple process, interoperational (intracyclic) breaks are divided into: batch breaks and waiting breaks.

Partion breaks appear when the transfer from operation to operation is carried out in batches, and each product included in the batch lies waiting for the assembly of the entire batch to be completed.

The wait break appears as a result of disproportion in performance on adjacent operations.

Factors affecting the duration of the production process:

1. Design and technological. The more complex the design, the greater the number of simple processes, the more difficult it is to organize the interconnection of processes, the full load of equipment and the minimum waiting time in the processing process.
2. Organizational nature. Organization of processes in time, organization of jobs, level of mechanization - automation of production processes.
3. Economic nature. Organization level labor processes, rational forms of labor stimulation, motivation labor activity, the level of equipment of workplaces, etc.

The basis of the production cycle is the technological cycle, which consists of operating cycles.

The operating cycle is the duration of processing one product (batch) in one operation of the process. It is determined based on the time spent:

1. to change the structure, properties and composition of the object of labor (main time).
2. time spent on the implementation of auxiliary techniques (loading, unloading, switching on, etc.).

Production cycle of products

To measure the process of manufacturing a product in time, an indicator is used - the production cycle. The production cycle is one of the most important technical and economic indicators, which is the starting point for calculating many indicators of the production and economic activities of an enterprise. On its basis, for example, the terms for launching the product into production are set, taking into account the timing of its release, the capacities of production units are calculated, the volume of work in progress is determined, and other planning and production calculations are carried out.

The production cycle of manufacturing a product (batch) is a calendar period of its being in production from the launch of raw materials and semi-finished products to the main production until the finished product (batch) is received. Production management.

In the conditions of production of a product consisting of many parts, a distinction is made between the cycle of manufacturing an article or product and the cycle of manufacturing parts or performing a group of operations. Reducing the cycle allows each production unit (workshop, section) to complete a given program with a smaller volume of work in progress. This means that the company gets the opportunity to accelerate the turnover of working capital, to fulfill the established plan with less expenditure of these funds, to release part of the working capital.

The production cycle consists of two parts: from the working period, i.e., the period during which the object of labor is directly in the manufacturing process, and from the time of breaks in this process.

The working period consists of the time of execution of technological and non-technological operations; the latter include all control and transport operations from the moment the first production operation is completed until the moment the finished product is delivered.

The production cycle Tc can be expressed by the formula:

TC \u003d Tvrp + Tvpr,
Tvpr - break time.

During the working period, technological operations are performed:

Tvrp \u003d Tshk + Tk + Ttr + Te,

The sum of the times of piece, control operations, transportation is called operating time (Topr):

Topr \u003d Tshk + Tk + Ttr.

In the operating cycle, the time of control operations Tk and the time of transportation of objects of labor Ttr are conditionally included, since in organizational they do not differ from technological operations.

Tshk \u003d Top + Tpz + Ten + Toto,

Where Top - operational time;
Tpz - preparatory and final time when processing a new batch of parts;
Ten - time for rest and natural needs of workers;
Toto - the time of organizational and technical maintenance (receipt and delivery of tools, cleaning the workplace, lubricating equipment, etc.).

Operational time Top, in turn, consists of the main Tos and auxiliary time Tv: Top = Tos + Tv.

Prime time is the actual time that work is being processed or completed.

Auxiliary time expressed by the formula:

TV \u003d Tu + Tz + Current,

Current - the time of the operational control of the worker (with the stop of the equipment) during the operation.

The time of breaks Tvpr is due to the work regime Trt, the interoperational laying of the part Tmo, the time of breaks for overhaul maintenance and equipment inspections Tr and the time of breaks associated with shortcomings in the organization of production Torg, that is:

Tvpr \u003d Tmo + Trt + Tr + Trade.

The time of interoperational sojourn Tmo is determined by the time of breaks in partion Tpar, waiting breaks Ir and picking breaks Tkp, that is:

Tmo = Tpar ​​+ Identity + Tcp.

Partion breaks Тpar occur during the manufacture of products in batches and are due to the aging of the processed parts until all the parts in the batch are ready for the technological operation.

Id wait breaks are caused by inconsistent durations of adjacent workflow steps.

Picking breaks Tkp occur during the transition from one phase of the production process to another.

Thus, in general, the production cycle is expressed by the formula:

Tts \u003d Topr + Te + Tmo + Trt + Tr + Trade.

When calculating the production cycle, it is necessary to take into account the overlap of some elements of time either by technological time or by the time between operations. Transportation time for objects of labor Ttr and time sampling Tk qualities are overlapping elements.

Based on the foregoing, the production cycle can be expressed by the formula:

Tc = (Tshk + Tmo) kper cor + Te,

Where nper is the coefficient of converting working days into calendar days (ratio of the number of calendar days (Dk) to the number of working days in a year (Dr), nper = Dk/Dr);
cor - coefficient taking into account breaks for overhaul maintenance of equipment and organizational problems (usually 1.15-1.2).

Based on the foregoing, the following conclusions can be drawn. The duration of the production cycle is expressed in calendar days or hours. The duration of the production cycle depends on the labor intensity of the products, the level of technology and technology, the mechanization and automation of production processes, the mode of operation, the organization of planning and logistics.

When calculating the duration of the production cycle, only those time costs are taken into account that are not overlapped by the time of technological operations (for example, time spent on control, transportation of products). Breaks caused by organizational and technical problems (untimely provision of the workplace with materials, tools, violation of labor discipline, etc.) are not taken into account when calculating the planned duration of the production cycle.

Production cycle time

The production process takes place not only in space, but also in time.

To characterize the flow of the production process in time, the concept of the production cycle is introduced.

The production cycle is a calendar period of time from the moment of launching raw materials, materials for the first operation of the cycle to the receipt of finished products.

The production cycle consists of:

1. Working period, or technological cycle - the time of the direct impact of the worker on the object of labor;
2. Time of natural processes (drying in air, cooling, stress relief, etc.);
3. Time of breaks related to the mode of operation.

Thus, the duration of the production cycle can be represented as follows:

Tts \u003d Trab + Test + Tper,
where TC is the duration of the production cycle;
Trab - the duration of the working period, including the time to perform technological, auxiliary, transport operations;
Test - the duration of natural processes;
Tper is the duration of the breaks.

The duration of the production cycle depends on the composition of production operations and breaks, on their duration and on the movement of objects of labor in the production process.

There are three types of movement of objects of labor in the process of their processing: serial, parallel, serial-parallel.

Shortening the production cycle

An increase in the degree of continuity of the production process and a reduction in the duration of the production cycle is achieved, firstly, by raising the technical level of production, and secondly, by measures of an organizational nature. Both paths are interconnected and complement each other.

Technical improvement of production goes in the direction of implementation new technology, progressive equipment and new Vehicle. This leads to a reduction in the production cycle by reducing the labor intensity of the actual technological and control operations, reducing the time for moving objects of labor.

Organizational measures should include:

Minimizing interruptions caused by interoperational waiting and batching interruptions through the use of a parallel-sequential method of movement of objects of labor and improvement of the planning system;
- Construction of schedules for combining various production processes, providing a partial overlap in the time of performing related work and operations;
- Reduction of waiting breaks based on the construction of optimized production schedules and the rational launch of parts into production;
- The introduction of subject-closed and detail-specialized workshops and sections, the creation of which reduces the length of intra-shop and inter-shop routes, reduces the time spent on transportation.

At the enterprise, the production cycle is reduced simultaneously in three directions: the time of labor processes is reduced, the time of natural processes is reduced, and various interruptions are completely eliminated or minimized.

Practical measures to reduce the production cycle follow from the principles of building the production process and, first of all, from the principles of proportionality, parallelism and continuity.

Reducing the time of labor processes in terms of operating cycles is achieved by improving technological processes, as well as improving the manufacturability of the product design.

The improvement of technological processes is understood as their complex mechanization and automation, the introduction of high-speed modes (for example, high-speed and power cutting, high-speed heating for forging and stamping), stamping instead of free forging, die casting and injection molding instead of sand casting, as well as concentration of operations. The concentration of operations may consist in multi-tool and multi-object processing or in combining several different technological operations in one working cycle (for example, when combining high-speed induction heating with blank stamping in one working cycle of a forging machine).

Improving the manufacturability of product designs lies in the maximum approximation of the latter to the requirements of the technological process. In particular, the rational division of the product design into units and small assembly units is an important condition for their parallel assembly and reducing the duration of the production cycle of assembly work.

The duration of transport operations can be significantly reduced as a result of the redevelopment of equipment based on the principle of direct flow, mechanization and automation of lifting and moving products using various lifting and transport vehicles.

Reducing the time of control operations is achieved by mechanizing and automating them, introducing advanced control methods, combining the time of technological and control operations.

The time of preparatory and final work included in this period of the cycle, especially the time for setting up equipment, is also subject to reduction. Equipment adjustment, as a rule, must be performed during non-working shifts, during lunch and other breaks. In factory practice, measures are successfully applied to reduce the period of this work, for example, the introduction of group processing of parts, standard and universal adjustments.

The duration of natural processes is reduced by replacing them with appropriate technological operations. For example, natural drying of some painted parts can be replaced by induction drying in the field of high-frequency currents with a significant (5-7 times) acceleration of the process. Instead of natural aging of castings of critical parts, which lasts 10-15 days or more, in many cases artificial aging in thermal furnaces for several hours can be applied.

The time of interoperational breaks can be significantly reduced as a result of the transition from sequential to serial-parallel and further to the parallel type of movement of objects of labor. It can also be reduced by organizing workshops and areas of subject specialization. Ensuring the territorial convergence of various stages of production, the subject structure of workshops and sections can significantly simplify intra-factory and intra-shop traffic routes and thereby reduce the time spent on inter-shop and intra-shop transfers.

The amount of breaks between shifts can be reduced even within the framework of the accepted mode of operation of the enterprise, workshop, site. For example, the organization of round-the-clock (three-shift) work on the production of leading parts for products that have a long processing cycle and determine the duration of the product cycle.

To reveal the reserves of reducing the production cycle (both labor processes and breaks), in practice, they resort to photography of the production cycle. Analyzing these photographs, it is possible to identify reserves for reducing the duration of the production cycle for each of its elements.

Organization of the production cycle

An indicator that characterizes the organization of production in time is the production cycle - the calendar period of time from the beginning to the end of the manufacture (repair) of a particular product (product) within one enterprise. Its duration does not depend on the number of simultaneously manufactured parts, assembly units or products and is determined by the period of time (calendar) during which raw materials, basic materials, semi-finished products, components are converted into a finished product (work performed). Its value is influenced by the nature of the products (work performed), the conditions and degree of mechanization (automation), the type, specialization and concentration of production, the equipment and technology used, the organization of labor and other factors. For example, the duration of the production cycle in mechanical engineering, in the production of furniture, often ranges from several hours to several weeks and even months.

The duration of the production cycle is used to draw up "calendar plans (production program) of enterprises and their divisions (workshops, sections, production lines, jobs), its standard value is to calculate the amount of work in progress. The production cycle is necessary for compiling calendar schedules movement of objects of labor (launch-release), calculation of the required amount of working capital.

In the structure of the production cycle, a working period is distinguished - the time during which the performer directly or indirectly affects the object of labor, it also includes machine (hardware) processes carried out under the supervision of an employee or control devices, as well as natural processes - the time during which objects of labor are modified under the influence of natural conditions (air drying of wood, products after painting), and breaks, subdivided, depending on the reasons that cause them, into breaks between operations of the production process - inter-operational and due to the mode of operation of the enterprise - inter-shift. The working period in discrete (discontinuous) processes is a relatively small part, and breaks are much larger.

Inter-operational breaks can be batch breaks and wait breaks. Partion breaks often occur when processing objects of work in transfer batches due to their lying in wait for the processing of the entire batch before transporting it to the next operation. In this case, each object of labor arriving at a given workplace as part of a batch lies twice - once before the start of processing and the second after its completion, until the entire batch of objects of labor is completed by processing at this workplace. Wait breaks occur when the end time of one and the start of another operation is inconsistent, i.e. in cases where the previous operation ends before it is released working time for the next operation.

A batch of objects of labor (production batch) is objects of labor of the same name and size, processed continuously at one or more workplaces during the general adjustment of equipment, i.e. with the same preparatory and final time for the operation. The execution time in the production cycle of technological operations is called the technological cycle, and the execution time of one production operation, during which one part or a batch of them is manufactured, is called the operating cycle.

Interoperational breaks, depending on the reasons for their occurrence, can be technical, due to the equipment used, the level of mechanization and automation of work; technological, depending on the technology used for manufacturing products (performance of work); organizational, associated with a lack of organization of jobs, untimely supply of raw materials and materials, fuel and energy, poor-quality repair and maintenance, other reasons. Organizational breaks are taken into account in the actual duration of the production cycle.

Breaks for technical and technological reasons are interconnected and condition each other, are caused most often by the nature of the objects of labor, their batch nature, and the uncoordinated activities of related operations. Breaks of this type also occur in the conditions of repair, machine-building, woodworking and other enterprises (the types of movement of objects of labor in production are discussed below). At enterprises in the chemical, metallurgical and other industries with a continuous production process, the duration of the production cycle coincides or almost coincides in time with the technological cycle; at enterprises with a discrete process - significantly exceeds it.

The mode of operation of the enterprise is established order and duration production activities enterprises and his structural divisions. It determines the time of work and breaks, the number of shifts per day and their duration in hours, the duration of the working week and the total operating time of the enterprise during the calendar period (month, quarter, year). It can be significantly influenced by the nature of the processed raw materials and the technology used, natural, climatic and other conditions. The duration of the working day (shift, week) is established in accordance with the current legislation.

There are continuous, intermittent and seasonal modes of operation of the enterprise. In continuous mode, the enterprise operates around the clock during the entire calendar period. It is used in metallurgical, chemical and other industries. Disruption of the continuity of the flow of technological processes in these industries is allowed only in connection with the requirement to control the use of equipment or its repair.

Discontinuous mode involves the operation of an enterprise (workshop) with predetermined breaks caused by the nature of the technological process, the operating conditions of the equipment, the length of the working day and week, the number of days off and holidays. It is typical for mechanical engineering, repair enterprises, forestry, woodworking and other industries.

The seasonal regime establishes the operation of an enterprise (workshop, lumber station, plot) during a certain season, the duration of which depends on the period of receipt of raw materials, the timing of its storage, conditions of extraction and use. The duration of the working season is determined either by the period of receipt of processed agricultural and other raw materials by the enterprise, the terms of its storage acceptable with modern technology, or the period (possible due to natural, climatic conditions) of extraction and its primary processing (processing). Such a regime is used, in particular, at the enterprises of the peat, fishing and hunting industries. It is widely used in forestry for sowing forest seeds and planting trees, when performing rafting and extraction of resin.

Business breaks include lunch breaks, breaks between work shifts, holidays and weekends. They, except for lunch, will be minimal or completely absent in continuous processes and reach their maximum value when working on a discontinuous working week in one shift.

The main form of operation of metallurgical, oil refining, and some chemical enterprises and workshops is a three-shift one, since a violation of the continuity of the technological process in these industries is allowed only in connection with the requirement to control equipment, to carry out preventive measures and regulated repairs. Such a regime assumes that the enterprise, the workshop operates continuously throughout the calendar year, unless a stop is provided (was not carried out) for scheduled equipment repairs. In cases where such a stop has taken place, the continuous operation will be less than a calendar year by the amount of downtime due to repairs.

Discontinuous daily operation of the enterprise (workshop) can be one-, two- or three-shift. The number of shifts in the work of machine-building and other enterprises with a discontinuous mode is set depending on the nature of the industry, demand for products, the availability of raw materials and labor, and other factors.

Main production cycles

The production cycle is the period of time for the manufacture of a product or batch from the moment raw materials and materials are launched into the main production until the finished product is received. It is expressed in calendar days or (in case of low labor intensity of the product) in hours.

Characteristics of the production cycle: structure and duration.

The production cycle consists of production time and break time.

Tc \u003d Tvrp + Tvpr,

Where Tvrp is the time of the workflow;
Tvpr - break time. The production time includes the duration of technological operations and the duration of auxiliary operations (technological maintenance of production).

The duration of technological operations is the time during which mechanical, chemical, physical and other effects on the objects of labor occur, resulting in a change in the shape, size, physical and chemical properties of the objects of labor.

Tvrp \u003d Tshk + Tk + Ttr + Te,

Where Tshk - piece-calculation time;
Tk - time of control operations;
Тtr is the time of transportation of objects of labor;
Te - the time of natural processes (aging, relaxation, natural drying, settling of suspensions in liquids, etc.).

The duration of auxiliary operations is the time spent on inter-shop and intra-shop movements of objects of labor, control, packaging, labeling, etc.

Tv \u003d Tu + Tz + Current,

Where Tu is the time of installation and removal of the part (assembly unit) from the equipment;
Tz - time of fastening and detachment of the part in the fixture;
Current - the time of the operational control of the worker (with the stop of the equipment) during the operation).

Breaks in work are divided into regulated and unregulated.

Scheduled breaks are included in each cycle if they are caused by waiting for the accumulation of a batch of products to transfer it to the next technological operation or a temporary stop in work due to the different duration of adjacent technological operations.

Unscheduled breaks are associated with downtime of equipment and workers due to unforeseen operating conditions for organizational and technical reasons (delay of raw materials, equipment breakdown) and therefore are included in the production cycle as a correction factor or are not taken into account at all. The time of breaks (Tvpr) is due to the mode of work (Trt), interoperational aging of the part (Tmo), time of breaks for overhaul maintenance and equipment inspections (Tr) and time of breaks associated with shortcomings in the organization of production (Torg): Tvpr \u003d Tmo + Trt + Tr + Trade.

The main component of the production cycle is the duration of technological operations, which constitutes the technological cycle.

(Tc): Tc = n * t / Km,

Where n is the number of items in the batch;
t is the duration of processing one item;
Km - the number of workplaces on which this operation is performed.

Production cycle period

The production cycle at the enterprise is a period of full turnover current assets used to service the production activities of the enterprise, from the receipt of raw materials and materials to the shipment of finished products to customers. The calculation of the duration of the production cycle in the business plan allows you to estimate the time spent on the production of goods.

The calculation of the duration of the period of the production cycle of the enterprise is carried out according to the following formula:

T=Tr+To+Tp

T is the duration of the production cycle,
Tr - time technological processing products (duration of the technological cycle),
To - the time of technological maintenance of the product (the time of transportation of the product, the time of its sorting, the time for quality control),
Tp - time of breaks in the work process (break time due to the mode of operation of the enterprise).

The production cycle can be measured in days, months, minutes, hours, etc.

Components of the production cycle

Production cycle length

The measurement of the production cycle using the path length is carried out from the first workplace, where the processing of the product and its components began, to the last one. The length of the production cycle is not a line, but the area on which machines, equipment, inventory are located, therefore, in practice, in most cases, it is not the length of the path that is determined, but the area and volume of the room in which production is located. There is a need for such a layout of workplaces that minimizes and facilitates communication and transport links between them. The shorter the path of movement of the product in the production process, the lower the cost of its inter-operational transportation, less production space is required and, as a rule, less time for processing.

Production cycle time

The duration of the production cycle in time is the interval of calendar time from the beginning of the first production operation to the end of the last one; measured in days, hours, minutes, seconds, depending on the type of product and the stage of processing. There are production cycles of the product as a whole, cycles of prefabricated units and individual parts, cycles for performing homogeneous operations, cycles for performing individual operations.

Working period

The working period is the time during which a direct impact on the object of labor is made either by the worker himself or by machines and mechanisms under his control; time of preparatory and final work; time of natural technological processes; maintenance time.

The time for performing technological operations and preparatory and final work is called the operating cycle.

The time of natural technological processes is the time during which the object of labor changes its characteristics without the direct influence of a person or technology (air drying of a painted product, growth and maturation of plants, etc.). To speed up production, many natural processes are carried out under artificially created conditions - for example, drying in drying chambers.

Technological maintenance time includes: quality control of product processing; control of operating modes of machines and equipment, their adjustment, easy repair; cleaning the workplace; transportation of blanks, materials, acceptance and cleaning of processed products.

The duration of the working period is influenced by various factors, for example: the quality of design work; the level of unification and standardization of products; the degree of accuracy of products (high accuracy requires additional processing, which lengthens the production cycle); organizational factors (organization of the workplace, placement of storage facilities, etc.). Shortcomings of an organizational nature increase the preparatory and final time.

The structure of the production cycle in time can be considered from three positions: the worker, mechanisms and objects of labor (the passage of blanks and parts). Part of the elements of the cycle can be combined (overlapped), for example, the main time - with technical and organizational maintenance, maintenance of parts - with the preparation of the workplace.

Break time

The time of breaks in work is the time during which no impact is made on the object of labor and there is no change in its qualitative characteristics, but the product is not yet finished and the production process is not completed. Distinguish between scheduled and unscheduled breaks. Regulated breaks are divided into intra-shift (inter-operational) and inter-shift (associated with the mode of operation).

Interoperative breaks are divided into:

Partion breaks - take place when parts are processed in batches. Each part or assembly, arriving at the workplace as part of a batch, lies before and after processing, until the entire batch passes through this operation;
- picking breaks - occur in cases where parts and assemblies lie due to the unfinished production of other products included in one set;
- waiting breaks - due to the inconsistency (non-synchronism) of the duration of adjacent operations of the technical process, they occur when the previous operation ends before the workplace is freed up for the next operation.

Inter-shift breaks include breaks between work shifts, lunch breaks, rest breaks for workers, weekends and holidays.

Unscheduled breaks are associated with organizational and technical problems (untimely provision of the workplace with materials, tools, equipment breakdown, violation of labor discipline, etc.). They are included in the production cycle in the form of a correction factor or are not taken into account.

Economic function of the production cycle

Without a scientifically based calculation of the duration of the production cycle, it is impossible to correctly draw up the production program of the enterprise and workshops, determine the technical economic indicators activities. The duration of the production cycle affects the timing of preparation for the production of new products, the turnover of working capital, is an important value in the organization of operational and production planning, logistics, etc.

The length of time for manufacturing the components of the product in the case exceeds the cycle time of the product itself due to the fact that a significant part of the components are manufactured in parallel.

To calculate the cycle of the entire product, it is necessary to have data on the production cycles of its elements. With the help of the duration of the production cycle, operational scheduling of the enterprise's work is carried out, including the distribution of production tasks to workshops, sections and workers; control over the timeliness of the execution of tasks in accordance with the orders of consumers.

The duration of the production cycle determines the volume of work in progress, which is the most significant part of working capital in terms of specific weight. Consequently, reducing the duration of the production cycle leads to an acceleration of the turnover of these funds and, ultimately, to an increase in the profit of the enterprise.

Working capital in the production cycle

The value of the standard of working capital in work in progress depends on four factors: the volume and composition of products, the duration of the production cycle, the cost of production and the nature of the increase in costs in the production process.

The volume of production directly affects the value of work in progress: the more products are produced, ceteris paribus, the greater will be the size of work in progress. A change in the composition of manufactured products affects the value of work in progress in different ways. With an increase in the share of products with a shorter production cycle, the volume of work in progress will decrease, and vice versa.

The cost of production directly affects the size of work in progress. The lower the cost of production, the lower the volume of work in progress in monetary terms. The increase in the cost of production entails an increase in work in progress.

The volume of work in progress is directly proportional to the duration of the production cycle. The production cycle includes the time of the production process, the technological stock, the transport stock, the time for the accumulation of semi-finished products before the start of the next operation (working stock), the time spent by semi-finished products in stock to guarantee the continuity of the production process (insurance stock), The duration of the production cycle is equal to the time from the moment of the first technological operation before acceptance of the finished product at the finished product warehouse. Reducing inventory in work in progress improves the use of working capital by reducing the duration of the production cycle.

To determine the rate of working capital for work in progress, it is necessary to know the degree of readiness of products. It reflects the so-called cost increase factor.

All costs in the production process are divided into one-time and incremental. Non-recurring costs include costs incurred at the very beginning of the production cycle - the costs of raw materials, materials, purchased semi-finished products. The remaining costs are considered incremental. The increase in costs in the production process can occur evenly and unevenly.

Product production cycle

When converting objects of production into a specific product, they go through many main, auxiliary and service processes that occur in parallel, parallel-sequentially or sequentially in time, depending on the production structure that has developed at the enterprise, type of production, level of specialization of production units, forms of organization. zation of production processes and other factors. The totality of these processes that ensure the manufacture of a product is commonly called the production cycle, the main characteristics of which are its duration and structure.

The duration of the production cycle for the manufacture of products (regardless of the number of simultaneously manufactured parts or products) is the calendar period of time during which raw materials, basic materials, semi-finished products and finished components are converted into finished products, or, in other words, this is a period of time from the moment the production process begins to the moment the finished product or batch of parts, assembly units is released.

The duration of the production cycle, as a rule, is expressed in calendar days or hours (with low labor intensity of products).

Knowledge of the duration of the production cycle for the manufacture of all types of products (from the manufacture of blanks, parts to the assembly of products) is necessary:

1) to draw up the production program of the enterprise and its divisions;
2) to determine the timing of the start of the production process (launch) according to the timing of its completion (release);
3) for calculations of the normal value of work in progress.

The duration of the production cycle depends on the time of labor and natural processes, as well as on the time of interruptions in the production process. During labor processes, technological and non-technological operations are performed. The execution time of technological operations in the production cycle is the technological cycle. The execution time of one operation, during which one part, a batch of identical parts or several different parts is manufactured, is called the operating cycle.

Non-technological operations include transportation of objects of labor and product quality control.

Natural processes are those that are associated with the cooling of parts after heat treatment, with drying after painting parts or other types of coatings, and with the aging of the metal.

Breaks, depending on the reasons that caused them, can be divided into interoperational (inside cycle), intershop and between shifts.

Interoperational breaks are due to the time of batching and waiting and depend on the nature of the processing of a batch of parts in operations. Partion breaks occur because each part, entering the workplace as part of a batch of similar parts, lies twice: once before the start of processing, and the second time after the end of processing, until the entire batch passes through this operation.

Wait breaks are caused by inconsistent durations of adjacent workflow steps. These breaks occur when the previous operation ends before the workspace is freed up for the next operation.

Intershop breaks are due to the fact that the deadlines for the completion of the production of component parts of parts of assembly units in different shops are different and the parts lie in anticipation of completeness. This waiting (breaks in picking) occurs with a complete-node planning system, i.e. when finished blanks, parts or assemblies must “lay out” due to the incompleteness of other blanks, parts, assemblies included together with the first in one set. As a rule, such breaks occur during the transition of products from one stage of production to another or from one workshop to another.

Inter-shift breaks are determined by the mode of operation of the enterprise and its divisions. These include weekends and holidays, breaks between shifts (with a two-shift regime, the third shift) and lunch breaks (conditionally).

The structure and duration of the production cycle depend on the type of production, the level of organization of the production process and other factors. Engineering products are characterized by a high share of technological operations in the total duration of the production cycle. The reduction of the latter is of great economic importance. As a rule, the duration of the production cycle is determined for one part, batch of parts, one assembly unit or batch of units, one product. At the same time, it should be borne in mind that any item or set of items to be manufactured at the enterprise or in its divisions is called a product.

When calculating the duration of the production cycle of manufacturing a product, only those time spent on transport and control operations, natural processes and breaks that are not overlapped by the operating cycle are taken into account.

Reducing the duration of the production cycle is of great economic importance. The shorter the duration of the production cycle, the more products per unit of time, all other things being equal, can be produced at a given enterprise, in a workshop or on a site; the higher the use of fixed assets of the enterprise; the less the enterprise's need for working capital invested in work in progress; the higher the return on assets, etc.

In factory practice, the production cycle is reduced simultaneously in three directions: the time of labor processes is reduced, the time of natural processes is reduced, and various interruptions are completely eliminated or minimized.

Types of production cycle

The production cycle is one of the most important technical and economic indicators, which is the starting point for calculating many indicators of the production and economic activities of an enterprise. On its basis, for example, the terms for launching the product into production are set, taking into account the timing of its release, the capacities of production units are calculated, the volume of work in progress is determined, and other planning and production calculations are carried out.

The most important parameter of the organization of the production process in time is the production cycle for the manufacture of an object of labor, the provision of a service or the performance of work from preparatory operations to the final ones. The duration of the production cycle consists of working time and break time.

The working period for the manufacture of an object of labor consists of the time of technological operations, transport and storage operations and control operations. In turn, the time of technological operations consists of preparatory and final time and piece time. The preparatory and final time is spent at the beginning of the work shift on preparing the workplace, debugging equipment, fixtures, installing tools, and at the end of the work shift - on removing fixtures, tools, etc. This time is spent on a batch of work items processed during the shift.

Breaks during working hours are divided into natural processes (drying, normalization after heat treatment and other operations that take place without human intervention), organizational breaks (waiting for the workplace to be vacated, delayed delivery of components, etc.), regulated breaks (lunch breaks, rest, etc.).

The duration of the production cycle of manufacturing the product as a whole is calculated after plotting the flow of a complex process of assembling the product and calculating the duration of the production cycles for manufacturing piece parts or their batches. This work is done by technologists.

The production process is a combination of objects and tools of labor, as well as living labor in space and time, functioning to meet the needs of production. This is a complex systemic concept, consisting of a set of the following particular concepts: the object of labor, the tool of labor, living labor, space, time, satisfaction of needs. The production process is heterogeneous in its structure, it consists of many interconnected sub-processes, during which individual parts, assemblies are created, and their connection by assembly allows to obtain the necessary product.

Production processes are divided into the following types:

1) basic;
2) auxiliary;
3) serving.

In turn, the main production processes are divided into:

A) preparatory (preparatory);
b) transforming (processing);
c) final (assembly).

The main ones include the processes of processing, stamping, cutting, assembly, painting, drying, installation, i.e., all operations that result in changes in the shape and size of objects of labor, their internal properties, surface condition, etc.

Auxiliary processes are designed to ensure the normal flow of the main ones. These processes are not directly related to the subject of labor, they include: the manufacture of tools and technological equipment, repairs, the production of electricity for the needs of the enterprise, etc.

Service processes include product quality control, production process, transport and storage operations.

Ancillary production - workshops or sections of an industrial enterprise that process waste from the main production or produce products that do not correspond to the specialization of this enterprise.

Side production - workshops in which products are made from production waste or the recovery of used auxiliary materials for production needs is carried out.

The development and improvement of all types of processes must occur in concert.

The production process also consists of simple and complex sub-processes, depending on the nature of the operations on the object of labor. A simple manufacturing process is a sequential relationship of manufacturing operations that results in a finished or partial product. Complex refers to the process of manufacturing a finished product by combining several partial products.

Depending on the amount of work required to achieve the final result of the process, full and partial production processes are distinguished. The complete process includes the whole complex of works necessary to obtain the final result of the process. A partial process is an unfinished part of a complete process. For the purpose of specialization, individual partial processes form working complexes, the structure of which is characterized in terms of their elemental, functional, and organizational composition.

The elemental composition of work complexes includes an integrated and purposeful interaction of objects of labor, means of labor and labor force, i.e., the purposeful movement of objects of labor through the stages of the production process, at each of which the objects of labor are exposed to the influence of means of labor and labor force.

The functional composition is characterized by the functional specialization of working complexes into main, auxiliary and service ones. The organizational structure provides for the division of work complexes according to the hierarchical level of organizational elements: company, plant, workshop, site, workplace.

The organization of production processes in time is based on the analysis of compliance with the principles of proportionality, continuity, parallelism, straightness, rhythm, etc. Let's consider these principles.

Proportionality - the principle, the implementation of which ensures equal throughput of different jobs of one process, proportional provision of jobs with information, material resources, frames, etc.

Long production cycle

The Tax Code of the Russian Federation has established a special procedure for recognizing income and expenses in the manufacture of products with a long technological cycle. However, the time frame at which the cycle is considered long is not clearly defined. It is only said that this is a production that continues for more than one tax period. Let's figure it out, taking into account the new clarification of the financiers.

So, production with a long technological cycle is mentioned in paragraph 2 of Article 271 and Article 316 of the Tax Code of the Russian Federation. It follows from them that these are productions that last more than one tax period. If the contract for the manufacture of such products does not provide for the stages of delivery of work, then the income from the sale must be distributed in accordance with the principle of formation of manufacturing costs. These articles do not contain any other definitions.

From a literal reading of these provisions, it can be assumed that we are talking about the production of products, the manufacture of which takes more than one year. After all, the duration of the tax period for calculating income tax is just a year (clause 1, article 285 of the Tax Code of the Russian Federation).

Such long periods are required, as a rule, for the manufacture of equipment for heavy and power engineering, ships, aircraft, etc. For such industries, the need to recognize income and expenses evenly or in accordance with the principle of forming expenses seems quite logical.

Otherwise, during the manufacturing period, the enterprise will increase the amount of work in progress, in addition, it may receive a loss. After all, indirect costs in the taxation of profits are recognized in the reporting period in which they actually arose.

As you can see, the main tax document under the production with a long technological cycle understands the period when more than one tax period passes from the start of production to its transfer to the buyer.

However, officials think otherwise. By such long-term production, they mean production that begins in one tax period and ends in the next. Moreover, regardless of the number of days of production in each of these parts. This was stated, for example, in the letter of the Ministry of Finance of Russia No. 03-03-04/4/160 and in the letter of the Ministry of Taxes of Russia No. 02-5-10/54.

Unfortunately, the financiers did not change their approach to this problem in their last letter No. 03-03-06/1/384.

In our opinion, financiers approach the problem of a long technological cycle in a very formal way. It is no coincidence that paragraph 2 of Article 271 and Article 316 of the Tax Code of the Russian Federation provide for such proceedings special conditions income recognition.

Most likely, under such productions, legislators meant the manufacture of products that lasts several months, or even several years. In other cases, it simply does not make sense to distribute income and expenses in a special manner.

However, taking into account the financiers' letters, the company will have to defend its point of view in court. Although there are already examples of arbitration practice that will help in this (see, for example, the decision of the Federal Antimonopoly Service of the North-Western District No. A42-2476 / 2006). But there is also a decision that was made in favor of the tax authorities (see decision Arbitration Court Sverdlovsk region No. А60-2086/2008-С8).

Distribution of income and expenses

The legislators only pointed out that income from “long-term contracts” must be recognized not at a time when the product is transferred to the customer, but in the process of its manufacture. Article 316 of the Tax Code of the Russian Federation only states that the principles and methods of distribution must be approved in the accounting policy of the enterprise.

Financiers in letter No. 03-03-04 / 4/160 propose to distribute the price of the contract between the reporting periods during which it is performed in one of the following ways:

- evenly, that is, the contractual cost must be divided in proportion to its duration in days;
- in proportion to the share of the actual expenses of the reporting period in the total amount of expenses provided for in the estimate.

If the first method is quite simple, then the second requires the preparation of an estimate of the costs of manufacturing products.

Production and commercial cycle

Production and commercial cycle modern enterprise involves a complex structure of receipt of assets necessary for the activity. Material and non-material. Stocks that are used unevenly.

Therefore, the calculation is carried out on the average of the following values:

Remaining raw materials. Both basic and additional material, and other values;
Balance of received and issued advances;
Costs in long-term technological processes or in an unfinished stage of production;
Quantity finished goods, not shipped to the consumer;
Accounts receivable;
Accounts payable.

Full turn Money time, as a rule, does not coincide with the production cycle. In many ways, it depends on the specifics of the enterprise and its structural organization. For this reason, it is customary to consider as the main indicator precisely financial activity, according to which the production and commercial cycle will be determined. Involved tangible and intangible assets that are in the process of continuous production activities are accounted for according to the procedures recommended by law.

Continuity of production is ensured by financial security with own funds, borrowed funds and credits from suppliers in the form of necessary materials and raw materials.

In the process of production, there is an accumulation of finished products that are supplied to the consumer. Some of them are shipped on credit terms, from which the total receivables to the enterprise are formed.

The list of manufactured products presented by the production for individual items may have different demand. Current assets, short-term liabilities and deliveries of individual assets may differ significantly in terms of the timing of the overall indicators of the organization and its production and commercial cycle. However, the analysis is done on the basis of the results of the entire enterprise.

The good performance of successful companies in different countries of the world is based on the observance of the following rules:

Improvement of work with suppliers. Contracts are drawn up in such a way that materials arrive in the right quantities by a precisely defined date.
Enterprise funds. Optimization and intelligent management of all cash flows. The best results are shown when the previous paragraph is completed. There are no costs for storing an excess amount of raw materials, components and elements. Payment schemes include mostly regular payments, which allows you to plan long-term projects.
Loans and receivables. Making the most of everything financial instruments can significantly increase the turnover of capital. An optimal system for placing orders and debt collection work, including factoring, stabilizes the actual operation of the enterprise.

Stages of the production cycle

Any process can be divided into production stages. The stage of production is a technologically completed part of the production process, characterized by such changes in the object of labor that cause its transition to another state.

In agriculture, the stage (partial production process) ends, as a rule, with a certain intermediate result. In crop production, these include the emergence of seedlings, obtaining seedlings of vegetables, a grown crop on the vine, threshed grain, a field filled with fertilizers; in animal husbandry - the resulting offspring, reared young animals of a certain sex and age group, etc.

Partial production processes (stages) are divided into operations. Each operation is carried out directly by a worker (or a group of workers) at a separate workplace on the same object of labor with the help of the same tools; in other words, it is characterized by the completeness, homogeneity and immutability of the objects of labor (the cultivated field, plants, animals, feed, finished products, etc.) and the means of labor (tractor unit, combine, stationary machines and mechanisms, inventory, etc.), as well as immutability of the workplace. With a change in at least one of these factors, a new production operation begins.

Operations, like processes, are divided into main and auxiliary. The set of basic operations is usually called a technological process; it forms a basic part of the manufacturing process. The nature of the technological process to the greatest extent determines the organizational conditions of production.

The structure of the production process is the ratio of various types of operations in its composition. It depends on a number of factors: production technology, technical equipment of the enterprise, the level of organization of production and labor. Analysis of the structure often reveals opportunities for further improvement in the organization of production.

When organizing the production process in time, it is necessary to achieve the fulfillment of all partial processes at the minimum possible time to ensure the minimum duration of the production cycle.

The production cycle is called the calendar period of time from the start of production to the receipt of finished products and their delivery to the warehouse.

The production cycle includes two stages:

The time of the production process, which is called the technological cycle, or working period;
- the time of interruptions in the production process.

The technological cycle or working period is the time of performing the main operations, during which the worker himself, or machines and mechanisms under his control, directly affects the object of labor, as well as the time of natural technological processes that occur without the participation of people and equipment.

It includes:

Time for technological operations;
- time for the course of natural production processes (Test).

The time of interruptions in the production process is the time during which no impact is made on the object of labor and no change in its qualitative characteristics occurs, but the product is not finished and the production process is not completed.

Depending on the expediency, there are:

Scheduled (unavoidable) breaks;
- unscheduled breaks, which include organizationally removable breaks (breakdown of machines, absence of workers from work). When designing a production cycle, they are not included in its composition, but are taken into account when determining its actual duration.

The production cycle is characterized by duration (in days, hours) and structure, the ratio of time spent and various types of work and interruptions in the production process.

The duration of the production cycle is one of the most important characteristics of the level of organization of production. But each industry has its own characteristics, which decisively determine the duration of the production cycle. Thus, the production cycle of winter crops stretches for almost 330 days, spring cereals, sugar beets, potatoes for 120-150 days, live weight of large cattle for sale for meat from 420 to 500 days, for broiler chickens from 40 to 60 days (live weight 1.5-2 kg), and for the production of canned food tanks it takes several minutes. In agriculture, the stage of the production cycle in crop production is determined by the beginning of field work, and in animal husbandry by the birth of offspring.

The structure of the production cycle depends on the type of products produced, the features of the technological process of its production and the type of production. Therefore, in various industries, the structure of the production cycle at enterprises is different.

In crop production, the largest share of time is occupied by breaks - 80-90%, and in the field of product processing, the working period has the greatest weight.

Reducing the duration of the production cycle by improving equipment and technology, using continuous and combined technological processes, deepening specialization and cooperation, introducing progressive methods of organizing production can improve many economic indicators: reduce production costs, improve the use of production resources, increase production, increase labor productivity etc.

A task. Determine the duration of the technological cycle of processing the part

Determine the duration of the technological cycle of processing a part using different types of transfer of objects of labor. The planned batch is 30 pieces. Operations per unit and number of machines per operation are as below:

Solution.

In order to find the cycle time using the sequential method of transferring parts, you need to use the formula:

n- the number of parts in the processed batch pcs.

i- operation

m- the number of operations in the technological process

FROM і - the number of machines on which the part is processed at the i-th operation.

t i - piece time to perform the i-th operation, minutes

t eats - the duration of natural processes (we do not have them and are taken equal to zero)

Substitute the values ​​in the formula

T c. last= 30*(5/1 + 9/1 + 18/1 + 6/2 + 5/1 + 3/2) = 30*(5 + 9 + 18 + 3 + 5 + 1.5)=1245 minutes

T cycle.– total processing time of the technological process

R- the size of the transfer lot pcs.

(t/c) cor. - the duration of the execution of the smallest of two adjacent operations.

Substitute the values ​​in the formulas.

τ \u003d (30-5) * (5/1 + 9/1 + 6/2 + 6/2 + 3/2) \u003d 25 * (5 + 9 + 3 + 3 + 1.5) \u003d 25 * 41, 5 = 537.5 min.

Now let's find the duration of the parallel-sequential cycle.

T cycle = 1245 - 537.5 = 707.5 minutes

The task of a parallel sequential cycle is to pass the products of labor through all the stages of production as quickly as possible with the continuous operation of the machines.

In order to find the duration of a parallel cycle of parts transfer, we use the formula:

Substitute the values ​​into the formula.

Tc pairs = 5*(5/1+9/1+18/1+6/2+5/1+3/2)+(30-5)*(18/1)=5*(5+9 +18+3+5+1.5)+

25*18=5*41.5+25*18=207.5+450=657.5 minutes

The task of a parallel cycle of movement of parts is to pass the products of labor through all stages of production as quickly as possible.

We can find the parallelism factor using the formula:

T c steam - cycle time in parallel way of moving parts

Tc last - the duration of the cycle in a sequential way of moving parts.

Substitute the values ​​into the formula.

K steam \u003d 657.5 / 1245 \u003d 0.528

Answer: T c. last =1245 min. , T c p-p = 707.5 min. , T c steam \u003d 657.5 min.

A task. Determine Change in Parts Cycle Time

The batch of parts consists of 10 parts, which are processed in a parallel-sequential type of movement. The technological process of processing parts consists of 6 operations t 1 = 2, t 2 = 9, t 3 = 6, t 4 = 2, t 5 = 3, t 6 = 4 min. It is possible to combine the fifth and sixth operations into one without changing the duration of each. The size of the transport lot is 1. Determine how the duration of the technological cycle of processing parts will change.

In order to find the time of a parallel sequential cycle of movement of parts, we use the formula.

The purpose of the course project is to form students a clear systemic understanding of production, organization and planning machine shops engineering companies. Mastering the concept of designing production at the site level, knowing the main methodological provisions of the general approach and assessing the technical and economic efficiency of the projected option is the main task of this course project.

The initial data for the implementation of the course project are: an individual task, literary and reference sources, reference materials for graduation and course design.

The course project is drawn up in the form of a settlement and explanatory note on standard sheets of A4 paper. A sample title page is included in the appendix. At the beginning of the note, its contents are given with an indication of the pages, and at the end - a list of used literature and reference materials.

All calculations are made in the form of tables (table forms are given in the relevant sections of the guidelines). Each table is accompanied by an explanation of the calculation procedure, indicating the source of the initial data. The number of the literary source according to the list is put down in square brackets.

The settlement and explanatory note should contain the following sections:

Introduction.

Calculation of the program for launching parts.

Calculation of the standard batch size of parts.

Calculation of the frequency of repetition of production.

Calculation of the duration of the production cycle of a batch of parts.

Calculation of the required amount of equipment.

Calculation of capital costs for building and equipment. This section should contain a layout diagram of the main equipment in the form of a draft plan.

Calculation of the number and fund wages industrial and production personnel. The same section provides a calculation table of summary indicators for labor and wages.

Calculation of the design cost of production.

The main technical and economic indicators of the site.

Financial and economic evaluation of the investment project.

Conclusions on the project.

Introduction

The introduction contains a description of the individual task: the technological process underlying the production, the composition of the equipment, the type of blanks and the main material.

Calculation of the program for launching parts (assemblies)

The production process in mechanical engineering is called the set of actions necessary for the production finished products. The basis of the production process is the technological process of manufacturing products, during which there is a change in the qualitative state of the production object. To ensure the uninterrupted execution of the technological process of manufacturing the product, auxiliary processes are also needed. Various stages of the production process in a machine-building plant can be carried out in separate workshops or in one workshop.

Production processes are divided into flow and non-flow. Under the flow production process is understood such a process in which workpieces, parts or assembled products are in motion during their production, and this movement is carried out with a constant cycle in the considered period of time. Non-flow production is understood as production in which semi-finished products in the process of their manufacture are in motion with different durations of operations and lying between them. In this course project, non-linear production will be considered.

Release program - the number of products to be manufactured per unit of time (year, quarter, month). In the individual task of the course project, the program for the production of finished parts is installed.

On the basis of the production program accepted for calculation, a program for launching it into production should be calculated.

The number of parts to be launched in the workshop (at the site) within a month (for each part included in the kit) is determined by the following formula:

Nz = Nvyp + (-) N np, (1)

where Nz is the number of parts put into production within a month (the amount of technically acceptable marriage in the machine shop is not taken into account by the course project);

Nvyp - the number of manufactured finished parts (the number of products or sets of parts to be produced, multiplied by the number of parts of this name, going to one product in the set);

N np - change in the total balances of work in progress (backlogs) at the end of the month in physical terms.

The specified calculation is performed in table 1.

Table 1 - Parts launch program calculation

Batch method of organizing production

The organization of the production process largely depends on the type of production in the enterprise. The type of production is a classification category of production, distinguished on the basis of the breadth of the nomenclature, the stability of the volume of output and the specialization of jobs. There are three main types of organization of production: single, serial and mass. In this course project, students need to organize a medium-scale production process that takes place within the production area of ​​a machine-building enterprise.

production site name the part of the volume of the workshop, in which the workplaces are located, united by transport and storage devices; means of technical, instrumental and metrological maintenance; means of site management and labor protection.

A serial manufacturing process is a process in which a relatively limited range of products is periodically manufactured in quantities determined by batches or batches. The basic principle of this type is the manufacture of the entire batch (series) as a whole, both in the processing of parts and in assembly. The concept of "batch" often refers to the number of parts, "series" - to the number of machines launched into production at the same time. The medium batch manufacturing process is the classic form of the batch method. This type of production is characterized by the use of machine tools: universal, specialized, automated, modular; universally adjustable tooling is used; qualification of workers - average.

Achieving uniform work with the batch method is ensured by the development of a number of standards that organize the production process. The most important of them are: the size of the batch of parts, the duration of the production cycle for manufacturing a batch of parts, the repeatability period for launching batches.

Parts Batch Calculation Methods

First way is to find such a number of parts in the batch, at which the total cost per part takes the minimum value. So, with an increase in the batch of parts from 100 to 600 pieces, the cost of changeover is reduced by 6 times.

Second way calculation of a batch of parts is based on the condition that the processing time of a given batch of parts at any workplace should not be less than a shift. This condition is explained by the desire to prevent the readjustment of equipment for processing other parts during one shift. In this case, the calculation is based on the minimum unit operation time (Tshm) spent in the manufacture of the part in this workshop. The calculation of the batch of parts is carried out according to the formula:

N \u003d Tcm / T pcsm × K n, (2)

where Tcm is the changeable fund of the equipment operation time, h;

Тshtm - the minimum piece time of the operation;

Third way calculation of a batch of parts is based on the condition of the most complete use of the equipment. It is this calculation method that is proposed to be used by students in a course project to calculate the standard size of a batch of parts. The calculation is based on the maximum allowable ratio between the preparatory-final time (Tpz) and piece time (Tsht) of the leading operation. The lot size calculated for the driving part operation is mandatory for all other operations. leading in this case, the operation with the longest preparatory-final time is considered. The calculation of the batch of parts (N) is carried out according to the formula:

N \u003d Tpz / T pcs × Kn, (3)

where T pz - preparatory and final time for the leading operation;

T piece - piece time for the leading operation;

Кн - coefficient of equipment adjustment.

N \u003d Σ Tpz / ΣT pcs × Kn. (3')

The equipment setup coefficient characterizes the maximum allowable ratio of setup time to piece time. The sizes of adjustment coefficients are determined by industry research institutes, taking into account the type of production, the material consumption of parts. So, for large-scale production, the adjustment factor is determined in the range from 0.03 to 0.06; and small-scale production - 0.1.

When determining the batch size for material-intensive parts, the setup factor is selected depending on the cost of the part and the number of operations assigned to one workplace. For example, when the cost of parts is 2-15 rubles and the number of operations assigned to one workplace is 10, the adjustment factor is 0.03; at 20 operations -0.04; with 30 operations - 0.06.

When determining the adjustment factor, you can focus on the weight and overall dimensions of the manufactured parts. So, for large parts weighing 5-10 kg, the adjustment factor is taken - 0.03; for medium parts weighing from 1 to 5 kg, the adjustment factor is 0.05; for small parts weighing less than kg, the adjustment factor is assumed to be 0.07. In the individual task for the implementation of the course project, data on the weights of manufactured parts are given, so it is preferable to use the last option for choosing the adjustment factor.

Determining the standard batch size of parts

The calculation of the standard batch size of parts is carried out in the following sequence.

On the basis of technological maps for the processing of parts, the leading operation is determined. The choice of the leading operation is made only by machining operations. Equipment and operations of other types of processing (thermal, galvanic, etc.) are not taken into account, as well as machines for manual operations. It must be borne in mind that machines within individual groups of equipment, for example, screw-cutting lathes (code

STV-1, STV-2, STV-3, STV-4 and STV-5), vertical milling machines (code VF-1), longitudinal milling machines (codes PF-1 and PF-2), etc. are combined into one group.

This group is used to calculate the leading operation for each part and its individual operations. It is impossible to carry out the specified calculation as a whole for a wide group of equipment (for example, turning, milling, drilling, etc. machines).

Table 2 shows the choice of the leading operation for five groups of machines (longitudinal milling, screw-cutting, copy-milling, slotting and vertical drilling).

Table 2 - Selection of the leading operation by groups of machines (conditional example)

Part No.	Machine groups
	Longitudinal milling PFO-1		Screw-cutting lathes STV-1		Copy-milling KOPF-4		Slotting		Vertical drilling SVS-2
					82

The total preparatory-final ΣTpz and piece time ΣTsht is determined in Table 2 by sequentially adding these times for each group of machines in relation to the data given in the corresponding technological maps for processing parts. The specified calculation is carried out for individual operations of the technological process. Since the largest ΣTpz turned out to be in the copy-milling group of machines, the copy-milling operation will be the leading one. If ΣTpz is the same for two or more groups of machines, then the leading operation is the one that corresponds to the smallest ΣTsht.

Having determined the leading operation, the minimum batch size of parts is calculated according to the formula (3'):

N min \u003d ΣTpz / Kn * ΣTsht, (3`)

where Nmin is the minimum lot size, pcs;

ΣТпз - total preparatory and final time for the leading operation of the set;

ΣTsht - total piece time for the leading operation of the set;

Кн – coefficient of equipment adjustment.

If the weight and overall dimensions of the parts are so different that Kn takes on different values, then the calculation of the minimum lot size of parts is carried out according to the heaviest part with the corresponding Kn.

The minimum batch size obtained by formula (3`) is adjusted to suit specific production conditions.

When establishing the standard batch size of parts, the following basic rules should be followed:

1. The batch size of parts must be equal to or a multiple of the monthly launch program for that part;

2. The number of parts in the batch must be such that their processing at one workplace requires at least half a shift (240 min), but no more than a shift (480 min). At the same time, this calculation is made for an operation that requires a minimum piece time for machining one part.

Frequency of repetition of production

The frequency of repetition of production (the rhythm of the batch) is understood as the period of time between the launch or release of two consecutively manufactured batches of items of this denomination.

The calculation of the frequency of launch - release of a batch of parts (batch rhythm) is made according to the following formula (4):

P \u003d Tp / Nzap *N norms, (4)

where P is the frequency of launch-release of a batch of parts, days;

Tp - the period for which the launch program is installed, days (the number of working days in a month);

N zap - the program for launching parts for the month, pcs;

N norms - standard batch size of parts, pcs.

5. Determination of the duration of the production cycle

lots of parts

The efficiency and technical and economic indicators of the production process depend on its organization in time. One of the indicators is the duration of the production cycle. Under duration of the production cycle is understood as the period of time from the moment the product (assembly, part) is put into production until the moment of complete manufacture and acceptance by the technical control department.

With the same task, with the same norms of time for an operation, changing only the path and type of movement of objects of labor in time, it is possible to control the duration of the production process. The result depends on the duration of the operation, the number of units of production and the number of simultaneously working machines in this operation.

The number of items moving simultaneously from one operation to another is called transfer party.

There are three main types of movement of parts in the production process: sequential, parallel and parallel-sequential (mixed).

The sequential type of movement of parts through operations is characterized by the fact that the entire batch of parts is transferred from operation to operation as a whole. The duration of the cycle with a sequential combination of operations is the largest and is calculated by the formula:

T c pos = ∑Tsht ×n , (5)

where ∑Tsht is the processing time of one part in all operations;

n is the number of parts in the batch.

At parallel movement, the object of labor is immediately transferred from one operation to another, and production is carried out simultaneously at all operations. The cycle duration for a parallel type of movement is determined by the formula:

Tc steam \u003d ∑Tsht + (n-1) T max, (6)

where T max is the execution time of the longest operation.

With a parallel type of movement of objects of labor, the duration of the technological cycle is sharply reduced, but there are downtimes at workplaces where the duration of the operation is less than the most time-consuming main operation. In connection with this, the parallel type of movement is justified in the case when the time of various operations is approximately equal or a multiple of each other, i.e. under conditions of continuous production.

parallel-serial the type of movement of objects of labor is characterized by the fact that the execution of the subsequent operation begins before the end of the processing of the entire batch of parts at the previous operation. With this type of movement of parts, adjacent operations overlap in time due to the fact that they are performed in parallel for some time. With a parallel-sequential type of movement of parts for operations, the cycle time is determined by the formula:

T c mix \u003d ∑ C + n * T to, (7)

where ∑ С is the sum of offsets (С 2 means the first offset of the 2nd operation

regarding the 1st; respectively C 3 means offset

3rd relative to 2nd, etc.);

T to - the processing time of the part at the final operation;

m is the number of operations for manufacturing a part;

Let T m be the processing time of the part at the next operation.

If in the previous operation the processing of the part will require less or equal time compared to the subsequent one, i.e.

T m -1 ≤ Tm, then the offset Cm = T m -1, and when T m -1 > Tm, then the offset is determined by formula 7.1:

Cm \u003d n * T m -1 - (n-1) Tm. (7.1)

Another way to determine the duration of a cycle in a parallel-sequential type of movement is the following formula:

T c mix \u003d ∑Tsht + (n-1) [∑Tdl- ∑Tkor], (8)

where ∑Tdl is the time of the total duration of all long-term operations;

∑Tcor - duration time of all short operations.

To determine the duration of operations, a diagram is built. Under the long-term understand operations located between two less long. Short transactions are those that are located between two long ones. Operations located on a slope are not included in the calculation and are not included in the sum of long and short operations.

In mass production, serial and parallel-sequential types of movement of a batch of parts are used.

The duration of the production cycle consists of a working period and breaks. The working period consists of the sum of the time of technological operations, the sum of the time between operations and the sum of the time between shifts. The duration of technological operations and preparatory and final work in total form an operating cycle. Therefore, the duration of the production cycle in calendar days is determined by the formula (9):

∑Tpz+ n ∑Tsht * K steam, (9)

TC calends \u003d 60 * Tcm * C * K v.n.

where Tc calendar is the duration of the production cycle of a batch of parts, calendar days (excluding weekends and holidays);

n is the standard batch size;

∑Тsht - the total rate of piece time for all operations in the manufacture of this part;

∑Tpz - the total rate of preparatory and final time for all manufacturing operations of this part;

Kpar - coefficient of parallelism; Kpar \u003d Tc mix / Tc after;

60 - conversion factor to hours;

Tcm - normal shift duration, hour;

C is the number of working shifts per day;

sq.n. - the planned coefficient of fulfillment of the norm (to simplify the calculations, Kv.n. in the course project is taken only for machine work);

Km.o. - the average coefficient of interoperational time, which is equal to 1.25-2.0; this coefficient shows the time between shifts and within shifts, as well as the time of technical control and the time of transportation of parts within the workshop.

To check the possibility of executing the entire program for the launch of parts within a month, they proceed from the determined duration of the production cycle for processing a batch of parts and make an additional calculation using the following formula:

Tc about \u003d (A-1) × P + Tc + D, (10)

where Tc about - the total duration of the production cycle of processing the entire program for the launch of parts of each item during the month, cal.days;

A - the number of batches launched during the month (determined by dividing the program for launching parts of each item by the standard batch size of parts);

P - the frequency of launching batches of parts, days;

Tc - the duration of the production cycle of a batch of parts, days;

D is the number of weekends and holidays in a month.

If the total duration of the production cycle for processing the entire program exceeds the number of working days in a month, it is necessary to switch from a sequential type of movement of a batch of parts to a parallel-serial one or increase the number of shifts in the section.

The calculation of the duration of the production cycle, both for a batch of parts and for the entire program for putting them into production, is carried out in Table 3.

When calculating the duration of the production cycle T p.c, only those time costs are taken into account that do not overlap with the time of technological operations (for example, time spent on control, transportation of products). Breaks caused by organizational and technical problems (untimely provision of the workplace with materials, tools, violation of labor discipline, etc.) are not taken into account when calculating the planned duration of the production cycle. When calculating the duration of the production cycle, it is necessary to take into account the peculiarities of the movement of the object of labor through the operations that exist at the enterprise. Usually one of three types of combination of operations is used: serial, parallel, parallel-serial.

At consistent movement, the processing of a batch of the same-named objects of labor at each subsequent operation begins only when the entire batch has been processed at the previous operation.

Example 1 Suppose you want to process a batch consisting of three items (n = 3); then the number of processing operations (t = 4), the time norms for operations are: t 1 = 10, t 2 = 40, t 3 = 20, t 4 = 10 min.

For this case, the cycle time is:

T c. last = 3 (10 + 40 + 20 + 10) = 240 min.

Since a number of operations can be performed not at one, but at several workplaces, the duration of the production cycle with sequential movement in the general case has the form:

T c. last = , (2.14)

where t i - piece rate of time of the i-th operation;

Ci- the number of jobs.

At parallel movement, the transfer of objects of labor to the next operation is carried out individually or by a transport batch immediately after processing at the previous operation:

T c. steam = , (2.15)

where R - the size of the transport party, pcs;

tmax - execution time of the longest operation;

Cmax - the number of jobs in a long-term operation.

For the above example: R= 1.

T c. steam = (10 + 40 + 20 + 10) + (3 - 1) × 40 = 160 min.

At parallel the form of movement, the duration of the production cycle is significantly reduced.

At parallel-serial In the form of movement, objects of labor are transferred to the next operation as they are processed at the previous piece by piece or by a transport batch, while the time for performing adjacent operations is partially combined in such a way that a batch of products is processed at each operation without interruptions. The transfer of the transport batch p t to the next operation can be carried out without waiting for the completion of work on the entire batch of products, subject to the condition of continuity of work for n ser,

When organizing parallel-sequential movement, two options for combining operations are possible:

a) from a previous short operation to a subsequent long operation;

b) from the previous long operation to the subsequent short operation;

In each of the options, a reduction in the technological cycle by the value τ = (n ser - p t) × (t core / C about core) is achieved.

The duration of the production cycle can be defined as the difference between the duration of the cycle for a sequential type of movement and the total time saved compared to a sequential type of movement, due to the partial overlap of the execution time of each pair of adjacent operations:

T c.p-p = T c.p - = (2.16)

For example, 1 p = 1.

T c. par-last = 240 - = 160 min.

With a parallel-sequential combination of technological operations, the cycle time T c.p.p. in calendar days is determined by the formula:

where 1/0.7 is the coefficient of converting working days into calendar days;

n and p - the number of products in the series and in the transport lot;

m is the number of technological operations performed;

T m.o - the duration of the interoperational waiting and the time of transportation from the previous to the next workplace;

T eat - the duration of the natural process;

ΣT pcs.cor - the total time rate of short operations, which is found in a sequential selection of operations, comparing them sequentially with each other in pairs, for all technological operations;

T cm - shift duration, T cm = 8 hours;

f cm is the number of shifts per day.

For clarity and clear execution, a graph of the duration of the production cycle is built, shown in Figure 2.7.

Figure 2.7 - Graph of the duration of the production cycle

Rules for constructing a graph of the duration of the production cycle.

1. Parallel-sequential type of movement:

a) in the case of a transition from a short preceding operation to a longer one, the transfer is carried out after the first transport lot;

b) in the case of a transition from the previous long-term operation to a short one, the transfer is carried out from the last transport batch of the long-term operation, and the rest are completed by the amount:

τ = (n ser - p t) × t i .

2. Parallel type of movement:

a) first, the technological cycle of the 1st transport batch is built for all operations without technological waiting;

b) then the schedule of the “main” - the longest operation is completed, taking into account its continuity;

Uninterrupted operation (with minimization of inter-operational expectations) at technological operations can be achieved by synchronizing all other operations, subject to the condition:

The duration of the production cycle is influenced by many factors: technological, organizational and economic. Technological processes, their complexity and diversity, technical equipment predetermine the processing time of parts and the duration of assembly processes. Organizational factors of the movement of objects of labor in the process of processing are associated with the organization of jobs, labor itself and its payment.

Organizational conditions even more influence the duration of auxiliary operations, service processes and breaks. Economic factors determine the level of mechanization and equipment of processes (and, consequently, their duration), the standards of work in progress. The faster the production process takes place (the shorter the duration of the production cycle), which is one of the elements of the circulation of working capital, the greater will be the speed of their turnover, the greater the number of revolutions they make during the year.

As a result, there is a release of monetary resources, which can be used to expand production at a given enterprise. For the same reason, there is a reduction (absolute or relative) in the volume of work in progress. And this means the release of working capital in their material form, i.e. in the form of concrete material resources.

Production capacity of the enterprise

The production capacity of an enterprise or workshop directly depends on the duration of the production cycle. Under production capacity refers to the maximum possible output in planning period. And therefore it is clear that the less time is spent on the production of one product, the greater the number of them can be manufactured in the same period of time.

Labor productivity with a reduction in the duration of the production cycle increases as a result of an increase in the volume of output due to an increase in production capacity, which leads to a decrease in the share of labor of auxiliary workers in a unit of output, as well as the share of labor of specialists and employees. The cost of production with a reduction in the production cycle is reduced due to a decrease in the cost of a unit of production of the share of general factory and workshop costs with an increase in production capacity.

Thus, reducing the duration of the production cycle is one of the most important sources of intensification and increasing the efficiency of production at industrial enterprises. The reserve for reducing the duration of the production cycle is the improvement of technology and technology, the use of continuous and combined technological processes, the deepening of specialization and cooperation, the introduction of methods of scientific organization of labor and maintenance of workplaces, the introduction of robotics.

It is necessary to build schedules for the movement of a batch of parts and calculate the duration of the technological cycle for various types of movements, if it is known that the batch of parts consists of 5 pieces, the technological process includes 5 operations: t1= 2; t2 = 9; t3= 5; t4 = 8; t5= 3. Shipment size R= 1 piece Each operation is performed on one machine.

Solution.

1. The duration of the technological cycle of processing a batch of parts with the sequential movement of objects of labor is calculated by the formula (1)

where P- the number of parts in the batch, pieces;

t i- the norm of piece time for i- operations, min;

C i - number of jobs for i-th operation;

t- the number of operations in the technological process.

Tc last \u003d 5 x (2 + 9 + 5 + 8 + 3) \u003d 135 min \u003d 2.25 hours (2)

The calculation is shown in Figure 19.

Figure 19 - Graph of the duration of the technological cycle with the sequential movement of a batch of parts

2. The duration of the technological cycle of processing a batch of parts with parallel-sequential movement of objects of labor is determined by the formula (3)

where R - the size of the transport lot, pcs.;

t ki - the shortest time between i-th pair of related operations, taking into account the number of pieces of equipment, min.

T c pp \u003d 5 x (2 + 9 + 5 + 8 + 3) - (5 - 1) x (2 + 5 + 5 + 3) \u003d 75 min \u003d 1.25 hours (4)

The calculation is shown in Figure 5.

Figure 20 - Graph of the duration of the technological cycle with parallel-sequential movement of parts

3. The duration of the technological cycle of processing a batch of parts with parallel movement of objects of labor is determined by the formula

where t i max- the norm of time of maximum duration i-th operation, taking into account the number of jobs, min;

T c pairs \u003d (5 - 1) x 9 + 1 x (2 + 9 + 5 + 8 + 3) \u003d 63 min. (6)

The calculation is shown in Figure 21.

Figure 21 - Graph of the duration of the technological cycle with the parallel movement of a batch of parts

conclusion

As a result of the test in the discipline "Technology and organization of products and services", the student considers the main theoretical and applied aspects of organizing the production of products and services, and also masters basic approaches to organizing production processes and acquires skills for optimizing them.

Undoubtedly, the knowledge, skills and abilities acquired during the performance of this test work will allow students to successfully apply the acquired knowledge in solving the following problems:

Studying the foundations of organization theory;

Studying the methods of complex diagnostics of industrial socio-economic systems;

Studying the methods of making organizational decisions;

Mastering the methods of organizing the complex preparation of the production of new products;

Mastering the methods of choosing a rational type and form of organization of production;

Implementation of the principles of formation of the organizational culture of production;

Implementation of the principles of rationalization and design of the structure of production systems;

Mastering the methods of operational-calendar planning of socio-economic organizations of production;

Mastering the methods of organizing the main, auxiliary and service industries;

Studying the functions of operational management of production;

Mastering methods for assessing the effectiveness of the organization of production.

The study of the basics of the discipline "Technology and organization of products and services" is the initial stage in the development of general cultural and professional competencies and is logically connected with the study in senior courses of such disciplines as "Woodworking technology", "Fundamentals of technologies for wood chemical and petrochemical industries", "Development and implementation of systems quality”, “Quality audit”, “Technology of service provision”, “Models and tools for improving the activities of the organization”, “Means and methods of quality management”, “Competitiveness management”.

Bibliographic list

1. Goldstein, G.Ya. Innovation management[text] : Tutorial/ G.Ya. Goldstein. - Taganrog: Publishing House of TRTU, 1998. - 132 p.

2. Organization of production and enterprise management [text]: textbook. for economy specialties of universities / O.G. Turovets [and others]; ed. O.G. Turovets. - M. : INFRA-M, 2009. - 540 p.

3. Organization of production and enterprise management [text]: textbook / O.G. Turovets, M.I. Bukhalkov, V.B. Rodionov and others; ed. O.G. Turovets. - 2nd ed. – M.: INFRA-M, 2006. – 544 p.

4. Fatkhutdinov, R.A. Organization of production [text]: textbook / R.A. Fatkhutdinov. - 2nd ed. rework and additional – M.: INFRA-M, 2005. – 528 p.

5. Karpov, E.A. Organization of production and management [text]: textbook. allowance for universities / E.A. Karpov. - Stary Oskol: TNT, 2010. - 768 p.

6. Shepelenko, G.I. Economics, organization and planning of production at the enterprise [text]: textbook. allowance for econom. specialties of universities / G.I. Shepelenko. - Rostov n / DM .: PhoenixMart, 2010. - 600 p.

7. Ryazanova, V.A. Organization and planning of production [text]: textbook. allowance for universities / V.A. Ryazanova, E.Yu. Lyushina; ed. M.F. Balakin. – M.: Academy, 2010. – 272 p.

8. Organization theory. Organization of production at enterprises [text]: integrir. textbook allowance for econom. specialties of universities / A.P. Agarkov [and others]; under total ed. A.P. Agarkov. – M.: Dashkov i K°, 2010. – 260 p.

9. Organization and planning of production [text]: textbook. allowance for universities / A.N. Ilchenko [and others]; ed. A.N. Ilchenko, I.D. Kuznetsova. – M.: Academy, 2008. – 208 p.