11.1. Types of production and their technical and economic characteristics
The type of production is determined by a comprehensive description of the technical, organizational and economic features of production, determined by the breadth of the product range, regularity, stability and volume of production. The main indicator characterizing the type of production is the coefficient of consolidation of Kz operations. The operation consolidation coefficient for a group of workplaces is defined as the ratio of the number of all different technological operations performed or to be performed during the month to the number of workplaces:
where K opi is the number of operations performed at the i-th workplace;
K r.m - the number of jobs on the site or in the workshop.
There are three types of production: single, serial, mass.
Single production characterized by a small volume of production of identical products, the re-production and repair of which, as a rule, are not provided for. The consolidation factor for unit production is usually above 40.
Batch production is characterized by the manufacture or repair of products in periodically repeated batches. Depending on the number of products in a batch or series and the value of the consolidation coefficient of operations, small-scale, medium-scale and large-scale production are distinguished.
For small-scale production the coefficient of consolidation of operations is from 21 to 40 (inclusive), for medium-scale production - from 11 to 20 (inclusive), for large-scale production - from 1 to 10 (inclusive).
Mass production characterized by a large volume of output of products that are continuously manufactured or repaired over a long period of time, during which one work operation is performed at most workplaces. The coefficient of consolidation of operations for mass production is taken equal to 1.
Let's consider the technical and economic characteristics of each type of production.
Single and similar small-scale production characterized by the production of a wide range of parts at workplaces that do not have a specific specialization. This production must be sufficiently flexible and adapted to fulfill various production orders.
Technological processes in single production conditions are developed enlarged in the form of route maps for processing parts for each order; The sites are equipped with universal equipment and fixtures that ensure the production of parts of a wide range. The wide variety of jobs that many workers have to do requires them to have different professional skills, so highly skilled generalists are used in operations. In many areas, especially in pilot production, combining professions is practiced.
Organization of production in a single production environment has its own characteristics. Due to the diversity of parts, the order and methods of processing them, production areas are built according to a technological principle with equipment arranged in homogeneous groups. With this organization of production, parts pass through various sections during the manufacturing process. Therefore, when transferring them to each subsequent operation (section), it is necessary to carefully consider the issues of quality control of processing, transportation, and determination of workplaces for performing the next operation. Features of operational planning and management include timely completion and fulfillment of orders, monitoring the progress of each part through operations, ensuring the systematic loading of areas and workplaces. Great difficulties arise in organizing logistics. A wide range of manufactured products and the use of aggregated standards for the consumption of materials create difficulties in uninterrupted supply, which is why enterprises accumulate large stocks of materials, and this leads, in turn, to the depletion of working capital.
Features of the organization of unit production affect economic indicators. Enterprises with a predominance of a single type of production are characterized by a relatively high labor intensity of products and a large volume of work in progress due to the long storage of parts between operations. The cost structure of products is characterized by a high share of wage costs. This share is usually 20-25%.
The main opportunities for improving the technical and economic indicators of individual production are associated with bringing it closer to serial production in terms of technical and organizational level. The use of serial production methods is possible by narrowing the range of manufactured parts for general machine-building applications, unifying parts and assemblies, which allows us to move on to the organization of subject areas; expanding constructive continuity to increase the launch batches of parts; grouping parts that are similar in design and manufacturing order to reduce time for production preparation and improve the use of equipment.
Batch production is characterized by the production of a limited range of parts in batches repeated at certain intervals. This allows you to use special equipment along with universal ones. When designing technological processes, the order of execution and equipment of each operation are provided.
The organization of mass production is characterized by the following features. Workshops, as a rule, consist of closed areas where equipment is placed along the course of a standard technological process. As a result, relatively simple connections arise between workstations and the prerequisites are created for organizing the direct movement of parts during their manufacturing process.
The subject specialization of the sections makes it advisable to process a batch of parts in parallel on several machines that perform successive operations. As soon as the previous operation finishes processing the first few parts, they are transferred to the next operation until the entire batch is processed. Thus, in conditions of mass production, parallel-sequential organization of the production process becomes possible. This is its distinctive feature.
The use of one or another form of organization in mass production conditions depends on the labor intensity and volume of production of the products assigned to the site. Thus, large, labor-intensive parts, manufactured in large quantities and having a similar technological process, are assigned to one site with variable-flow production organized on it. Parts of medium size, multi-operational and less labor-intensive are combined into batches. If their launch into production is regularly repeated, group processing areas are organized. Small, low-labor parts, such as standardized studs and bolts, are secured to one specialized area. In this case, it is possible to organize direct-flow production.
Serial production enterprises are characterized by significantly lower labor intensity and cost of manufacturing products than individual enterprises. In mass production, compared to individual production, products are processed with fewer interruptions, which reduces the volume of work in progress.
From an organizational point of view, the main reserve for increasing labor productivity in serial production is the introduction of continuous production methods.
Mass production is characterized by the greatest specialization and is characterized by the production of a limited range of parts in large quantities. Mass production workshops are equipped with the most advanced equipment, allowing almost complete automation of the production of parts. Automatic production lines have become widespread here.
Technological processes of machining are developed more carefully, step by step. Each machine is assigned a relatively small number of operations, which ensures the most complete workload of work stations. The equipment is located in a chain along the technological process of individual parts. Workers specialize in performing one or two operations. Parts are transferred from operation to operation one by one. In conditions of mass production, the importance of organizing interoperational transportation and maintenance of workplaces increases. Constant monitoring of the condition of cutting tools, devices, and equipment is one of the conditions for ensuring the continuity of the production process, without which the rhythm of work on sites and in workshops will inevitably be disrupted. The need to maintain a given rhythm at all levels of production becomes a distinctive feature of the organization of processes in mass production.
Mass production ensures the most complete use of equipment, a high overall level of labor productivity, and the lowest cost of manufacturing products. In table 11.1 presents data on the comparative characteristics of various types of production.
Table 11.1
Comparative characteristics of various types of production
11.2. Forms of production organization
The form of organization of production is a certain combination in time and space of elements of the production process with an appropriate level of its integration, expressed by a system of stable connections.
Various temporal and spatial structural structures form a set of basic forms of production organization. The time structure of production organization is determined by the composition of the elements of the production process and the order of their interaction over time. Based on the type of temporary structure, forms of organization are distinguished with sequential, parallel and parallel-sequential transfer of objects of labor in production.
The form of organization of production with the sequential transfer of objects of labor is a combination of elements of the production process that ensures the movement of processed products across all production areas in batches of arbitrary size. Objects of labor are transferred to each subsequent operation only after the completion of processing of the entire batch in the previous operation. This form is the most flexible in relation to changes that arise in the production program, it allows for sufficient full use of the equipment, which makes it possible to reduce the cost of its acquisition. The disadvantage of this form of production organization is the relatively long duration of the production cycle, since each part lies waiting for the entire batch to be processed before performing the subsequent operation.
The form of organization of production with parallel transfer of objects of labor is based on such a combination of elements of the production process that allows you to launch, process and transfer objects of labor from operation to operation individually and without waiting. This organization of the production process leads to a reduction in the number of parts being processed, reducing the need for space required for storage and aisles. Its disadvantage is the possible downtime of equipment (workstations) due to differences in the duration of operations.
The form of organization of production with parallel-sequential transfer of objects of labor is intermediate between sequential and parallel forms and partially eliminates their inherent disadvantages. Products are transferred from operation to operation in transport batches. At the same time, continuity of use of equipment and labor is ensured, and a partially parallel passage of a batch of parts through technological process operations is possible.
The spatial structure of the organization of production is determined by the amount of technological equipment concentrated on the work site (the number of workplaces), and its location relative to the direction of movement of objects of labor in the surrounding space. Depending on the number of technological equipment (workstations), a distinction is made between a single-link production system and the corresponding structure of a separate workplace and a multi-link system with a workshop, linear or cellular structure. Possible options for the spatial structure of production organization are presented in Fig. 11.1. The workshop structure is characterized by the creation of areas in which equipment (workstations) are located parallel to the flow of workpieces, which implies their specialization based on technological homogeneity. In this case, a batch of parts arriving at the site is sent to one of the free workplaces, where it undergoes the necessary processing cycle, after which it is transferred to another site (to the workshop).
On the site with linear spatial structure equipment (workstations) is located along the technological process and a batch of parts processed at the site is transferred from one workplace to another sequentially.
Cellular structure production organization combines the characteristics of linear and workshop. The combination of spatial and temporal structures of the production process with a certain level of integration of partial processes determines various forms of organization of production: technological, subject, direct-flow, point, integrated (Fig. 11.2). Let's look at the characteristic features of each of them.
The technological form of organizing the production process is characterized by a workshop structure with sequential transfer of objects of labor. This form of organization is widespread in machine-building plants, since it ensures maximum equipment utilization in small-scale production and is adapted to frequent changes in the technological process. At the same time, the use of a technological form of organizing the production process has a number of negative consequences. A large number of parts and their repeated movement during processing lead to an increase in the volume of work in progress and an increase in the number of intermediate storage points. A significant part of the production cycle consists of time losses caused by complex inter-site communications.
Rice. 11.1. Options for the spatial structure of the production process
The subject form of production organization has a cellular structure with parallel-sequential (sequential) transfer of objects of labor in production. As a rule, all the equipment necessary for processing a group of parts from the beginning to the end of the technological process is installed at the subject area. If the processing technological cycle is closed within the site, it is called subject-closed.
Subject construction of sections ensures straightness and reduces the duration of the production cycle for the manufacture of parts. In comparison with the technological form, the object form allows reducing the overall costs of transporting parts and the need for production space per unit of production. However, this form of production organization also has disadvantages. The main one is that when determining the composition of the equipment installed on the site, the need to carry out certain types of processing of parts comes to the fore, which does not always ensure full loading of the equipment.
In addition, expanding the range of products and updating them require periodic redevelopment of production areas and changes in the structure of the equipment fleet. The direct-flow form of production organization is characterized by a linear structure with piece-by-piece transfer of objects of labor. This form ensures the implementation of a number of organizational principles: specialization, directness, continuity, parallelism. Its use leads to a reduction in the duration of the production cycle, more efficient use of labor due to greater specialization of labor, and a reduction in the volume of work in progress.
Rice. 11.2. Forms of production organization
With the point form of production organization, work is completely performed at one workplace. The product is manufactured where its main part is located. An example is the assembly of a product with a worker moving around it. The organization of point production has a number of advantages: it provides the possibility of frequent changes in the design of products and the processing sequence, the production of products of a diverse range in quantities determined by production needs; costs associated with changing the location of equipment are reduced and production flexibility is increased.
The integrated form of production organization involves the combination of main and auxiliary operations into a single integrated production process with a cellular or linear structure with sequential, parallel or parallel-sequential transfer of objects of labor in production. In contrast to the existing practice of separate design of processes of warehousing, transportation, management, processing in areas with an integrated form of organization, it is necessary to link these partial processes into a single production process. This is achieved by combining all workplaces with the help of an automatic transport and warehouse complex, which is a set of interconnected, automatic and warehouse devices, computer equipment designed to organize the storage and movement of objects of labor between individual workplaces.
The progress of the production process here is controlled using a computer, which ensures the functioning of all elements of the production process on the site according to the following scheme: search for the required workpiece in the warehouse - transportation of the workpiece to the machine - processing - return of the part to the warehouse. To compensate for deviations in time during the transportation and processing of parts, buffer warehouses for interoperational and insurance reserves are created at individual workplaces. The creation of integrated production sites is associated with relatively high one-time costs caused by the integration and automation of the production process.
The economic effect of the transition to an integrated form of production organization is achieved by reducing the duration of the production cycle for manufacturing parts, increasing the loading time of machines, and improving the regulation and control of production processes. In Fig. 11.3 shows equipment layout diagrams in areas with different forms of production organization.
Rice. 11.3. Layout diagrams of equipment (workstations) in areas with different forms of production organization: a) technological; b) subject; c) direct-flow: d) point (for the case of assembly); e) integrated
Depending on the ability to re-adjust for the production of new products, the above forms of production organization can be divided into flexible (re-adjustable) and rigid (non-re-adjustable). Rigid forms of production organization involve processing parts of the same type.
Changes in the range of products and the transition to the production of a structurally new series of products require redevelopment of the site, replacement of equipment and accessories. The hard ones include the continuous form of organizing the production process.
Flexible forms make it possible to ensure the transition to the production of new products without changing the composition of the components of the production process with little time and labor.
The most widespread forms of production organization at machine-building enterprises are currently flexible point production, flexible subject and flow forms.
Flexible point production involves the spatial structure of a separate workplace without further transfer of objects of labor during the production process. The part is completely processed in one position. Adaptability to the release of new products is carried out by changing the operating state of the system. A flexible subject form of production organization is characterized by the possibility of automatic processing of parts within a certain range without interruption for changeover. The transition to the production of new products is carried out by re-adjusting technical means and reprogramming the control system. The flexible subject form covers the area of sequential and parallel-sequential transfer of objects of labor in combination with a combined spatial structure.
The flexible, linear form of production organization is characterized by rapid readjustment for processing new parts within a given range by replacing tooling and fixtures, and reprogramming the control system. It is based on a row arrangement of equipment that strictly corresponds to the technological process with piece-by-piece transfer of objects of labor.
Development of forms of organization of production in modern conditions Under the influence of scientific and technological progress in engineering and mechanical engineering technology, significant changes are occurring due to mechanization and automation of production processes. This creates objective preconditions for the development of new forms of production organization. One of these forms, which has been used when introducing flexible automation tools into the production process, is the block-modular form.
The creation of production with a block-modular form of production organization is carried out by concentrating on a site the entire complex of technological equipment necessary for the continuous production of a limited range of products, and uniting a group of workers to produce the final product, transferring to them part of the functions of planning and managing production on the site. The economic basis for the creation of such industries is collective forms of labor organization. Work in this case is based on the principles of self-government and collective responsibility for the results of work. The main requirements for organizing the production and labor process in this case are: the creation of an autonomous system of technical and instrumental maintenance of production; achieving continuity of the production process based on calculating the rational need for resources, indicating intervals and delivery dates; ensuring the matching capacity of machining and assembly departments; taking into account established controllability standards when determining the number of employees; selection of a group of workers taking into account complete interchangeability. The implementation of these requirements is possible only with a comprehensive solution to the issues of labor organization, production and management. The transition to a block-modular form of production organization is carried out in several stages. At the pre-project survey stage, a decision is made on the advisability of creating such units in the given production conditions. An analysis of the design and technological homogeneity of products is carried out and an assessment is made of the possibility of assembling “families” of parts for processing within the production cell. Then the possibility of concentrating the entire complex of technological operations for the production of a group of parts in one area is determined; the number of workplaces adapted for the introduction of group processing of parts is established; the composition and content of the basic requirements for organizing the production and labor process are determined based on the intended level of automation.
At the structural design stage, the composition and relationships of the main components of the production process are determined.
At the stage of organizational and economic design, technical and organizational solutions are combined, ways to implement the principles of collective contracting and self-government in autonomous teams are outlined. The second direction in the development of forms of production organization is the transition to the assembly of complex units using the bench method, the abandonment of conveyor assembly through the organization of a mini-flow. Mini-flow was first introduced by the Swedish automobile company Volvo.
- Production here is organized as follows.
The entire assembly process is divided into several large stages. At each stage there are working groups of 15-25 assemblers. The team is located along the outer walls of a quadrangle or pentagon, inside of which there are cash registers with the parts necessary at this stage of assembly. The machines are assembled on self-propelled platforms, moving through larger operations within a given stage. Each worker completes his entire operation. The principle of flow with such an assembly system is completely preserved, since the total number of identical parallel working stands is such that the average specified flow cycle is maintained. The movement of platforms with assembled machines from one stage of assembly to another is monitored by a dispatch service using four computers.
Another solution to organizing continuous production is to maintain the conveyor system and include preparatory operations in it. In this case, the assemblers, at their own discretion, work either in the main or in the preparatory operations. These approaches to the development of the continuous form of production organization not only ensure an increase in labor productivity and improved quality, but also give assemblers a sense of satisfaction from work and eliminate the monotony of work.
11.3. Production organization methods
Production organization methods represent a set of methods, techniques and rules for the rational combination of the main elements of the production process in space and time at the stages of operation, design and improvement of production organization.
Method of organizing individual production used in conditions of single production or production in small batches and assumes: lack of specialization in the workplace; the use of widely-universal equipment, its arrangement in groups according to functional purpose; sequential movement of parts from operation to operation in batches. The conditions for servicing workplaces are different in that workers almost constantly use one set of tools and a small number of universal devices; only periodic replacement of dull or worn tools is required. In contrast, the delivery of parts to work stations and the adjustment of parts when issuing new work and accepting finished work occurs several times during the shift. Therefore, there is a need for flexible organization of transport services for workplaces.
Let's consider the main stages of organizing individual production.
Determination of the types and number of machines required to complete a given production program. When organizing individual production, it is difficult to accurately establish the range of products produced, therefore approximate calculations of the required number of machines are acceptable. The calculation is based on the following indicators: product removal from a unit of equipment q; number of machine hours required to process a set of parts for one product h. The accuracy of the aggregated calculations depends on how correctly the values of the indicated indicators are determined. The estimated number of machines Sp is determined by the formula
(11.2) where S p j is the estimated number of machines for the j-th group of equipment;
Q - annual production volume, pcs.; K cm j - work shift coefficient for the j-th group of equipment; F e j is the effective working time fund of one machine of the j-th group.
where t p is the standard time spent on repairing this equipment, % of the nominal fund; t p - standard time spent on setup, readjustment, relocation of this equipment, % of the nominal fund.
The nominal operating time of the machine depends on the number of calendar days D k and non-working days in the year D n, the adopted work shift schedule per day and is determined by the formula
(11.4)
where T hs is the average number of machine operating hours per day according to the adopted shift schedule.
The accepted number of machines for each group of equipment is established by rounding the resulting value to the nearest integer so that the total number of machines does not exceed the limits of their accepted number.
The equipment load factor is determined by the ratio of the calculated number of machines to the accepted one.
Coordination of the capacity of individual sections by power. The production capacity of a site equipped with the same type of equipment is determined as follows:
where S pr - accepted amount of equipment; K n.cm - standard equipment shift ratio; K is the rate of compliance with standards achieved in the base year for the site (shop); Pg - planned target to reduce labor intensity, standard hours.
The standard shift coefficient for equipment operation is determined based on the load of installed equipment, usually in a two-shift operating mode, taking into account the standard coefficient that takes into account the time the machines are under repair.
The conjugacy of individual sections in terms of power is determined by the formula
(11.6)
where K m is the coefficient of conjugation of sections by power; M y1, M y2 - the capacity of the compared sections (products of the 1st section are used to manufacture a unit of product of the 2nd section); Y 1 - specific consumption of products of the 1st division.
Organization of the workplace. Features of the organization and maintenance of workplaces are as follows: setting up the machine before starting work, as well as installing tools at workplaces, is carried out by the workers themselves, while workplaces must be equipped with everything necessary to ensure continuous operation; transportation of parts should be carried out without delays; there should be no excessive stock of workpieces at work sites.
Development of site planning. Individual production is characterized by the layout of areas by type of work. In this case, sections of homogeneous machine tools are created: turning, milling, etc. The sequence of locations in the workshop area is determined by the processing route for most types of parts. The layout should ensure the movement of parts over short distances and only in the direction that leads to the completion of the product.
The method of organizing flow production is used in the manufacture of products of one type or design series and involves a combination of the following special methods of organizational structure of the production process: location of workplaces along the technological process; specialization of each workplace in performing one of the operations; transfer of objects of labor from operation to operation individually or in small batches immediately after completion of processing; rhythm of release, synchronization of operations; detailed study of the organization of technical maintenance of workplaces.
The flow method of organization can be used if the following conditions are met:
- the volume of production is large enough and does not change over a long period of time;
- the design of the product is technologically advanced, individual components and parts are transportable, products can be divided into structural and assembly units, which is especially important for organizing the flow of the assembly;
- time spent on operations can be established with sufficient accuracy, synchronized and reduced to a single value; a continuous supply of materials, parts, and assemblies to work stations is ensured; Full load of equipment is possible.
The organization of continuous production is associated with a number of calculations and preparatory work. The starting point when designing a continuous production process is to determine the volume of production and the flow cycle. A cycle is the time interval between the launch (or release) of two adjacent products on a line. It is determined by the formula
where F d is the actual operating time of the line for a certain period (month, day, shift), taking into account losses for equipment repairs and regulated breaks, min; N 3 - launch program for the same period of time, pcs.
The reciprocal of the clock cycle is called the rate of operation of the line. When organizing continuous production, it is necessary to ensure such a pace to fulfill the production plan.
The next step in organizing continuous production is determining the need for equipment. Calculation of the amount of equipment is carried out based on the number of workplaces for process operations:
where C pi is the estimated number of jobs per process operation; t i - standard time for the operation, taking into account installation, transportation and removal of parts, min.
The accepted number of jobs C at i is determined by rounding the calculated quantity to the nearest whole number. It is taken into account that at the design stage an overload of 10-12% per workplace is allowed.
The workload coefficient Kz is determined by the formula
(11.9)
To ensure full equipment utilization and continuity of the production process during continuous production, synchronization (alignment) of operations over time is carried out.
Methods for synchronizing operations on metal-cutting machines
Ways to synchronize assembly operations
- Differentiation of operations. If the operating time standard is larger and not a multiple of the takt and the assembly process is easily differentiated, you can equalize the time spent on each operation by breaking it into smaller parts (transitions).
- Concentration of operations. If an operation is shorter in duration than a cycle, small operations or transitions configured in other operations are grouped into one.
- Combining operations. If the time required to complete two adjacent operations is less than the cycle time of the assembly line, you can organize the movement of a worker along with the product he is assembling, entrusting him with performing several operations. Once synchronization of operations on the production line has been achieved, a schedule of its operation is drawn up, making it easier to control the use of equipment and workers. The rules for constructing a line operation schedule are set out in 12.6.
- One of the main conditions for the continuous and rhythmic operation of production lines is the organization of interoperational transport.
In continuous production, vehicles are not only used to move products, but also serve to regulate the work cycle and distribute objects of labor between parallel workstations on the line.
Vehicles used in continuous production can be divided into driven and non-driven, continuous and intermittent.
Most often, in flow conditions, a variety of drive conveyor vehicles are used.
The speed of the conveyor belt during continuous movement is calculated in accordance with the production line cycle:
In the case of intermittent movement, the conveyor speed is determined by the formula
where l o is the distance between the centers of two adjacent workplaces (conveyor pitch), m; t tr - time of transporting the product from one operation to another, min.
The choice of vehicles depends on the overall dimensions, weight of the parts being processed, the type and number of equipment, the size of the cycle and the degree of synchronization of operations.
Flow design ends with the development of a rational line layout. When planning, it is necessary to comply with the following requirements: provide convenient approaches to workplaces for repair and maintenance of the line; ensure continuous transportation of parts to various work stations on the line; identify sites for accumulation of reserves and approaches to them; provide workplaces on the line for performing control operations.
The method of group organization of production is used in the case of a limited range of structurally and technologically homogeneous products manufactured in repeating batches. The essence of the method is to concentrate various types of technological equipment on a site to process a group of parts according to a unified technological process.
The characteristic features of such an organization of production are: detailed specialization of production units; launching parts into production in batches according to specially developed schedules; parallel-sequential passage of batches of parts through operations; execution of a technologically complete set of works at sites (in workshops).
Let's consider the main stages of organizing group production.
The final assembly of groups of parts assigned to a given section is carried out taking into account the labor intensity and volume of their production according to the relative labor intensity indicator Kd:
(11.13)
where N i is the volume of production of the i-th part in the planning period, pcs.; k oi number of operations in the technological process of processing the 1st part; tsht ij - piece processing time of the i-th part for the j-th operation, min; K inj - average coefficient of fulfillment of time standards.
This indicator is calculated for each detail of the analyzed population. Establishing summary indicators for parts of the last stage of classification ensures their synthesis into groups according to an accepted criterion.
The accepted number of machines is determined by rounding the resulting value S pi to a whole number. In this case, a 10% overload per machine is allowed.
Calculate the average equipment load factors for groups K zj and the section as a whole K z.u:
(11.14)
where S prj is the accepted number of machines; h is the number of equipment groups on the site.
To ensure economically feasible loading, it is established taking into account intra-site cooperation, and for unique and special machines, inter-site cooperation - by transferring some of the work from underloaded machines to machines of adjacent groups.
When reorganizing existing workshops, the number of organized areas can be determined by the formula
(11.16)
where P i is the turnout number of main workers, people; C m - shift work mode; N y - the standard of control for the master, expressed by the number of workplaces served by him; C p - average level of work on the site; K z.o - the average number of operations assigned to one workplace of the site during the month.
When designing new workshops, due to the lack of data on the attendance of the main workers, the number of sections is determined as follows:
Based on the analysis of the structural and technological classification and KD indicators, parts are selected and assigned to sections. The efficiency of group production is determined by the degree of isolation of production areas.
A section is closed if all operations for processing groups of parts are performed on it (technological closure) and the machines are not loaded with work on cooperation from other sections (production closure).
A quantitative assessment of the degree of isolation is determined using indicators:
(11.18)
(11.19)
where Kt.z is the coefficient of technological isolation; T S - labor intensity of manufacturing parts assigned to the site, h; T wi - processing time of the i-th part outside the site, h;
k is the number of parts whose processing cycle is not completed in this area; K p.z - coefficient of production isolation; T ni is the processing time of the i-th part manufactured at the cooperation site; m is the number of parts transferred for processing to a given site through inter-site cooperation.
The integral indicator of the degree of closure Kint is calculated by the formula
(11.20)
When K int = 1, the use of group production methods is most effective.
Method of organizing synchronized production. The basic principles of organizing synchronized production were developed in the 60s by the Japanese company Toyota. The synchronized production method integrates a number of traditional functions of organizing production processes: operational planning, inventory control, product quality management. The essence of the method is to abandon the production of products in large batches and create a continuous-flow multi-item production, in which, at all stages of the production cycle, the required unit or part is delivered to the site of the subsequent operation exactly at the required time.
The set goal is realized by creating group, multi-subject production lines and using the pull principle in managing the progress of production. The basic rules for organizing the production process in this case are:
- production of products in small batches;
- formation of series of parts and use of group technology in order to reduce equipment setup time;
- converting storage materials and semi-finished products into buffer warehouses;
- transition from a workshop structure of production to subject-specific divisions;
- transfer of management functions directly to performers.
Of particular importance is the use of the pull principle in managing the progress of production.
With a traditional system, a part moves from one area to another (the next one in the technological process) and then to the finished product warehouse. This method of organizing production allows you to use workers and equipment regardless of whether there is a demand for a given type of product. In contrast, with a just-in-time system, the production schedule is set only for the assembly area. No part is produced before it is needed in final assembly. Thus, the assembly area determines the quantity and order of launching parts into production.
Management of the progress of the production process is carried out according to the following principles: the volume, nomenclature and timing of the task are determined by the site (workplace) of the next stage of production; the rhythm of production is set by the section that closes the production process; the resumption of the production cycle at the site begins only if the corresponding order is received; the worker, taking into account the deadlines for delivery of parts (assembly units), orders the number of blanks (components) that is necessary to complete the task received; delivery of components (parts, assembly units) to the workplace is carried out within the time frame and in the quantities specified in the application; components, units and parts are supplied at the time of assembly, individual parts - at the time of assembly of units; necessary blanks - to start manufacturing parts; Only suitable products are transferred outside the site.
The functions of operational management of the production process are transferred to direct performers. A Kanban card is used as a means of communicating parts requirements.
In Fig. Figure 11.4 shows a diagram of the organization of synchronized production. The movement of containers with parts and kanban cards between areas is indicated by arrows on the diagram and is described below.
For example, supplying the grinding area with workpieces is carried out in the following order.
- As soon as the next batch of parts is processed at the grinding site, the vacated container with a consumption card is sent to an intermediate warehouse.
- At the warehouse, the consumption card accompanying the container is removed, placed in a special box - a collector, and the container with the production card attached to it is fed to the drilling area.
- The production card serves as a signal for the start of production. It plays the role of an outfit, on the basis of which parts are made in the required quantity.
- Parts for each completed order are loaded into an empty container, a production card is attached to it, and the full container is sent to a temporary storage location.
- From the intermediate warehouse, a container with workpieces and a consumption card, which is attached instead of a production card, arrives at the grinding area.
- production of parts begins only if a production card has been received. It is better to allow production to be suspended than to produce parts that are not needed;
- For each container there is only one transportation and one production card; the number of containers for each type of part is determined as a result of calculations.
The synchronized production method involves the introduction of an integrated quality management system, which is based on compliance with certain principles, including: control of the production process; visibility of the results of measuring quality indicators; compliance with quality requirements; self-repair of marriage; checking 100% of products; continuous quality improvement.
Quality control during production in accordance with the specified principles is carried out at all stages of the production process, at each workplace.
To ensure clarity of the results of measuring quality indicators, special stands are created. They explain to the worker and the administration what quality indicators are being checked, what the current inspection results are, what quality improvement measures are being developed and are in the process of being implemented, who has received quality awards, etc. In this case, the task of ensuring quality comes first, and fulfillment of the production plan is on the second.
The roles of departments and other technical control units, their powers, range of tasks, and methods are changing. Responsibility for quality is redistributed and becomes universal: each organizational unit, within its competence, is responsible for ensuring quality. In this case, the main responsibility falls on the product manufacturers themselves.
To eliminate defects and ensure quality, the production process may be suspended. Thus, at the Kawasaki plant in the USA, assembly lines are equipped with red and yellow warning lights. If difficulties arise, the worker turns on the yellow signal. If the defect is serious enough to require the line to be stopped, it lights up a red light.
The defect is corrected independently by the workers or the team that caused it. Each finished product is subject to control, and not a sample from a batch, and, where possible, components and parts.
The last principle is gradual improvement of product quality. The challenge is to develop and implement quality improvement projects at each production site. All personnel, including specialists from individual services, take part in the development of such projects. Ensuring the quality of work and achieving continuity of the production process in a synchronized production environment occurs through preventive maintenance of equipment, which includes recording the nature of the operation of each machine, carefully determining the need for preventive maintenance and the frequency of its implementation.
Rice. 11.4. Scheme of organization of synchronized production: I - route diagram of the production process; II - movement diagram of containers with kanban cards
Every day, a machine operator performs a number of operations to check his equipment. The start of the working day is preceded by lubrication, debugging of the machine, securing and sharpening of tools. Maintaining order in the workplace is considered a prerequisite for quality work. In domestic mechanical engineering, the implementation of the principles underlying the synchronized production method is possible in several stages.
First stage. Creating conditions to ensure an uninterrupted supply of production with the necessary materials.
Second phase. Organizing the launch of parts into production in batches, the size of which is determined by the needs of the assembly, based on a three- or five-day release of products.
In this case, the operational planning system is simplified as much as possible. The workshop (section, team) is given a task: quantity, name of parts that must be manufactured in a particular five-day or three-day period. The batch sizes, taking into account the applicability of parts and the five- or three-day production of machines, are determined by the production dispatch bureau (PDB) of the workshop. The order of launch and release is determined by the master and crew. The dispatch service accepts and takes into account only those sets of parts that are scheduled for delivery during this period. Outfits are also closed for payment. The schedule may be supplemented by emergency requirements due to defects or other reasons. Reducing batch sizes can lead to losses in productivity, which will impact workers' wages. Therefore, a temporary increase in the price may be offered.
Third stage. Organization of work according to the principle: “The worker, the team, the workshop are responsible for quality. A personal mark is given to each worker.”
Fourth stage. The introduction of a procedure in which the worker is engaged in performing his main work, provided that there is a need for it. Otherwise, it should be used where there is a labor shortage.
If a task is not completed, the worker or crew completes it overtime. Each case of task failure must be analyzed with the obligatory participation of the worker, the team, the workshop manager and the specific culprits. Footnotes
- The group method of manufacturing parts was developed by Dr. Tech. Sciences S.P. Mitrofanov. The main results of his work are reflected in the works “Scientific Organization of Machine-Building Production” (Moscow, 1976) and “Group Technology” (Moscow, 1986).
- This dependence was proposed by Dr. Econ. Sciences G.E. Slesinger.
ABSTRACT
in the course "Fundamentals of Economics"
on the topic: “Methods of organizing production”
1. Forms, types and methods of organizing production
The organization of production is a system of measures and activities aimed at the rational combination of labor with the material elements of production, tools and objects of labor. This system of measures is also aimed at the optimal combination of private production processes among themselves in space and time and, on this basis, at increasing production efficiency. There are forms of organization of social production, types of organization of production and methods of organizing production processes.
Forms of organization of production in general include concentration, specialization, cooperation and combination. Concentration is the process of concentrating the production of products on a limited number of enterprises and in their production divisions. The level of concentration depends, first of all, on the volume of product output, the unit capacity of machines, units, devices, technological installations, the number of similar equipment, the size and number of technologically homogeneous production facilities. To measure the level of concentration, indicators of production volume, number of employees, and in certain industries - the cost of fixed assets are used.
Specialization means the concentration at the enterprise and in its production units of producing homogeneous, similar products or performing individual stages of the technological process. There are technological, subject and detail specializations. Technological specialization is the separation of enterprises, workshops and areas in order to perform certain operations or stages of the production process (for example, spinning, weaving and finishing factories in the textile industry). Subject specialization involves the concentration of production at an enterprise (in a workshop) of completely finished products (for example, motorcycles, bicycles, dishes, bakery products, etc.). Detailed specialization, being a type of subject specialization, is based on the production of individual parts and parts of finished products (motors, bearings, etc.).
In the practice of enterprises, there is often a combination of all forms of specialization: procurement shops and areas are built according to technological characteristics, processing ones - according to detail, assembly - according to subject matter. To measure the level of specialization of enterprises and its divisions, the following indicators are used: the share of main (core) products in the total volume of production; the number of groups, types and types of products produced by the enterprise; share of specialized equipment in its total fleet; number of items of parts processed on a unit of equipment; number of operations performed per unit of equipment, etc.
The prerequisites for increasing the level of specialization are standardization, unification and typification of processes. Standardization establishes strictly defined quality standards, shapes and sizes of parts, assemblies, and finished products. It creates the prerequisites for limiting the range of products and increasing the scale of its production. Unification involves reducing the existing diversity in types of structures, shapes, sizes of parts, blanks, assemblies, materials used and selecting the most technologically and economically feasible ones. Process typification consists of limiting the variety of production operations used and developing standard processes for groups of technologically homogeneous parts. However, it should be borne in mind that the implementation of the considered prerequisites for specialization should not worsen the consumer properties of the finished product or reduce the demand for it.
In a competitive environment, in some cases, it is more preferable for an enterprise to diversify production, which involves a variety of areas of activity by expanding the range of products. Specialization in the production of a limited range of products aimed at meeting clearly defined market needs is characteristic of relatively small enterprises.
Cooperation involves production connections between enterprises, workshops, and areas jointly participating in the production of products. It is based on detailed and technological forms of specialization. Intra-factory cooperation is manifested in the transfer of semi-finished products from one workshop to another, in the servicing of main departments by auxiliary ones. It contributes to a more complete utilization of production capacity and the elimination of bottlenecks, and ensures improved performance of enterprises as a whole. The main indicators characterizing the level of cooperation include: the share of parts and semi-finished products received through cooperative supplies in the total volume of manufactured products; the number of enterprises cooperating with this enterprise; share of parts and semi-finished products supplied externally, etc.
Combination is the combination in one enterprise of production, sometimes from different industries, but closely related to each other. A combination can take place:
based on a combination of successive stages of product manufacturing (textile, metallurgical and other plants);
based on the integrated use of raw materials (oil refining, chemical industry enterprises);
when separating waste processing divisions at an enterprise (forestry, leather and other industries).
Indicators characterizing the level of combination are the quantity and cost of products obtained from the raw materials processed at the plant; the proportion of raw materials and semi-finished products processed into the subsequent product at the place of their production (for example, cast iron into steel, steel into rolled products); the share of by-products in the total volume of production of the plant, etc.
The organization of production at an enterprise is a form of unit division of labor. There are the following levels of production organization at the enterprise:
organization of production at the workplace - the optimal combination of means of labor, objects of labor, labor;
intra-shop labor organization - associated with the organization of labor at sites and the organization of labor between sites;
inter-shop organization of production - organization of production processes carried out by shops, aimed at their functioning as a single whole.
There are three types of production organization:
element-by-element - all elements of the production process
must correspond to each other, which is the original
the moment of its organization;
spatial - associated with a certain level of organization of workshops and sections and the corresponding level of the production structure of the enterprise;
time section of production organization - the optimal combination in time of the beginning and end of individual production processes interconnected.
The degree of specialization and scale of production determine the type of production organization, and the degree of compliance with the basic principles of rational organization of the production process characterizes the method of production organization. The following methods of organizing the production process are distinguished:
in-line;
party;
individual.
In addition to methods of organizing the production process, it is necessary to distinguish between types of production organization, which include:
mass;
serial;
single production.
There is a relationship between methods of organizing the production process and types of organization of production:
The mass type of production organization corresponds to the flow method of production organization;
in conditions of a wide range of products, a serial type of production organization is used, which corresponds to the batch method of production organization. The serial type has three gradations: large-scale, medium-scale, and small-scale production;
A single type of production organization corresponds to an individual method of production organization.
The most economical is the mass type with a continuous production method. The most common is the serial type and batch method of organizing production.
2. Flow method of organizing production
Flow production is a form of production organization based on the rhythmic repetition of the time for performing main and auxiliary operations at specialized workplaces located along the flow of the technological process.
The flow method is characterized by:
reducing the range of products to a minimum;
division of the production process into operations;
specialization of jobs to perform certain operations;
parallel execution of operations at all workstations in the flow;
location of equipment along the technological process;
high level of continuity of the production process based on ensuring equality or multiple duration of execution of operations with the flow cycle;
the presence of special interoperational transport for transferring objects of labor from operation to operation.
The structural unit of continuous production is the production line. A production line is a set of workstations located along the technological process, designed to perform assigned technological operations and interconnected by special types of interoperational vehicles. Flow methods are most widespread in the light and food industries, mechanical engineering and metalworking, and other industries. The production lines existing in industry are varied. The classification of production lines is presented in table. 1. There are other classifications of production lines.
For the continuous production method, the following standards are used: tact, rhythm of the production line, conveyor pitch, total length and speed of the production line.
For continuous flow production, it is imperative to adhere to the principle of synchronization. The principle of synchronization is that the execution time of each operation must be equal to or a multiple of the calculated cycle of the production line. This is achieved by calculating the number of jobs at each operation. If the duration of an operation is equal to or less than the takt time, then the number of workstations and pieces of equipment is equal to the number of operations. If the duration of the operation is longer than the takt time, then several workstations are needed for synchronization.
Table 1. Classification of production lines
| Signs of classification |
Types of production lines |
| 1. Nomenclature of processed products (number of objects assigned for production on production lines) |
Constant-flow (single-subject and multi-subject) Variable flow Group multi-subject |
| 2. Degree of continuity of the production process |
Continuous (with a regulated rhythm and with a free rhythm) Intermittent (direct flow) |
| 3. Level of mechanization and automation |
Mechanized Complexly mechanized Automated |
| 4. Coverage of the production process |
District End-to-end |
| 5. Method of maintaining rhythm |
With a regulated rhythm With free rhythm With variable-regulated |
| 6. Method of transporting objects of labor |
Conveyor type Non-conveyor type (slopes, chutes, cranes, electric cars, etc.) |
| 7. Location of operations |
Working conveyor Distribution conveyor |
| 8. Degree of continuity of conveyor movement |
Continuous conveyors Pulsating Conveyors |
Piece time is the time required to complete all labor techniques for each individual operation. Let us present the initial data and perform the corresponding calculations.
The economic efficiency of the flow method is ensured by the implementation of all principles of production organization: specialization, continuity, proportionality, parallelism, straightness and rhythm. The disadvantages of flow organization of production are as follows:
The main requirements when choosing products for production using the in-line method include the sophistication and relative stability of their designs, large scale production, which does not always meet the needs of the market;
the use of conveyor transportation lines increases the transport backlog (work in progress) and makes it difficult to transfer information about product quality to other workplaces and areas;
The monotony of labor on production lines reduces the material interest of workers and contributes to an increase in staff turnover.
Measures to improve in-line methods include:
organization of work with variable tact and production line speed throughout the day;
transfer of workers during a shift from one operation to another;
the use of multi-operational machines that require regular switching of workers’ attention to different processes;
use of financial incentives;
introduction of aggregate-group methods of organizing the production process, production lines with a free rhythm.
The main direction of increasing the economic efficiency of continuous production is the introduction of semi-automatic and automatic production lines, the use of robots and automatic manipulators to perform monotonous operations.
3. Batch and individual methods of organizing production
The batch method of organizing production is characterized by the production of a different range of products in quantities determined by the batches of their launch and release. A batch is the number of products of the same name that are processed in turn at each operation of the production cycle with a one-time expenditure of preparatory and final time. The batch method of organizing production has the following characteristic features:
launching products into production in batches;
processing of several types of products simultaneously;
assigning several operations to a workplace;
wide application along with specialized universal equipment;
use of highly qualified personnel and broad specialization;
arrangement of equipment mainly in groups of similar machines.
Batch organization methods are most widespread in serial and small-scale production, procurement shops of mass and large-scale production, where high-performance equipment is used that exceeds the throughput capacity of associated machines and machines in other departments.
To analyze the batch method of organizing production, the following standards are used: batch size, launch-release frequency, work-in-progress stock size and serial production ratio.
The batch size is the main standard. Batch size is the number of parts of the same name processed at one workplace continuously with a one-time expenditure of preparatory and final time. The larger the batch size, the more fully the equipment is used, however, the volume of work in progress increases and the turnover of working capital slows down.
The time loss coefficient is defined as the ratio of preparatory and final time to the operating time of the equipment during which a given batch of parts is manufactured.
The size of the work in progress stock (backlog) is the stock of unfinished product within the production cycle. There are three types of backlogs - cyclic, insurance and revolving.
Working stock - products that are in warehouses, distribution rooms, storerooms, etc.
In terms of economic efficiency indicators (increased labor productivity, equipment use, cost reduction, working capital turnover), batch methods are significantly inferior to in-line methods. Frequent changes in the range of manufactured products and the associated re-adjustment of equipment, an increase in inventories of work in progress and other factors worsen the financial and economic results of the enterprise. However, opportunities are emerging to more fully satisfy consumer demand for various types of products, increase market share, and increase the content of workers’ work. The most important areas for increasing the efficiency of the batch method:
introduction of group processing methods;
implementation of flexible production systems (FPS).
The individual method of organizing production is characterized by the production of products in single copies or small non-repeating batches. It is used in the manufacture of complex unique equipment (rolling mills, turbines, etc.), special equipment, in pilot production, when performing certain types of repair work, etc. Distinctive features of the individual method of organizing production are:
uniqueness of the product range throughout the year;
use of universal equipment and special equipment;
arrangement of equipment into similar groups;
development of integrated technology;
the use of highly skilled workers with a wide range of skills;
a significant proportion of work using manual labor;
a complex system of organizing logistics, creating large inventories of work in progress, as well as inventories in the warehouse;
high costs of production and sales of products, low turnover of funds and level of equipment utilization.
The standards for the individual method of organizing production are:
calculation of the duration of the production cycle for manufacturing an order as a whole and its individual components;
determination of inventories or work in progress standards.
Directions for increasing the efficiency of the individual method of organizing production are standardization, unification of parts and assemblies, and the introduction of group processing methods.
4. Organization of production in auxiliary and service departments of the enterprise
The auxiliary and service departments of the enterprise include repair, tooling, transport, energy, warehousing, etc.
The main task of the repair facility is to maintain equipment in working condition and prevent its premature wear. The organization and procedure for carrying out repair work are regulated by standard regulations. The preventive maintenance system (PPR) covers a set of activities, including equipment care, between-repair maintenance, periodic preventive operations (inspections, accuracy checks, oil changes, flushing), as well as scheduled preventive maintenance (routine and major). The main standard of the PPR system is the repair cycle - the period of time between two next major repairs, which is measured in years. The number and sequence of repairs and inspections included in it constitute the structure of the repair cycle.
A feature of planning repair work is that a conventional repair unit is adopted as a unit of measurement for the volume of repair work, equal to the ratio of working time spent on repairing a screw-cutting lathe. Depending on the complexity and labor intensity of the repair, all equipment is divided into 11 groups of repair complexity. To calculate the volume of repair work in units of repairability, it is necessary to multiply the number of pieces of equipment undergoing repairs during the planning period by a coefficient equal to the number of the repairability group for each type of equipment.
The volume of repair work in the workshop in physical units of equipment is determined according to the structure of the repair cycle and the date of the last repair for each type of equipment and type of repair (current, major). All standards for time spent are developed per unit of repair complexity of each type of repair work, regardless of the type of equipment being repaired. Planning repair work includes the following calculations:
Types of repair work for each machine and unit and the timing of their implementation.
Labor intensity of repair work, labor productivity, number and wages of repair personnel.
The quantity and cost of materials and spare parts required for repairs.
Planned downtime of equipment for repair.
Cost of repair work.
The volume of repair work in workshops and the enterprise as a whole, broken down by quarter and month.
The production program of the repair shop is determined by multiplying the norms of labor intensity of repair operations by the volume of repair work for the corresponding types of repairs in units of repair complexity. Calculation of the need for materials, spare parts and semi-finished products is made on the basis of material cost standards per unit of repair complexity and the volume of repair work. The ratio of the total equipment downtime for repairs to the annual operating time of the equipment is the percentage of equipment downtime for repairs.
The instrumental economy is designed to solve the following problems:
uninterrupted supply of tools to all production departments of the enterprise;
organization of rational operation of tools and devices;
reduction of tool inventories without compromising the normal course of the production process;
reducing the cost of maintaining tool equipment.
The tool economy consists of units for the supply of tools, their restoration, repair, adjustment and sharpening, a central warehouse and distribution storerooms involved in storing, completing and issuing tools. The tool can be classified according to a number of characteristics. Depending on their role in the production process, they are divided into working, auxiliary, control and measuring tools, fixtures, dies, and molds. Depending on the nature of use, the tool can be special or universal (normal).
Expenditure fund - the amount of tools that is consumed in carrying out the production program of the enterprise; Its calculation is based on tool life standards and wear time. The wear time is equal to the period of time the tool operates between two sharpenings, multiplied by the number of possible sharpenings. The rational organization and planning of tool management is based on tool life standards and the amount of tool inventory.
A revolving fund is created for the uninterrupted supply of tools to workshops, sites and workplaces. It includes stocks in warehouses, in workshop tool and dispensing storerooms, tools at workplaces, in sharpening, repair, restoration and inspection. The amount of tool stock in the warehouse is determined according to the “maximum-minimum” system using the following calculation algorithm:
the minimum stock of tools of each type is determined as the product of the daily demand for it by the number of days for urgent delivery of the next batch;
the “order point” stock is determined as the sum of the daily requirement for a tool multiplied by the number of days of its normal receipt, and the minimum stock;
The warehouse stock as a whole is determined as the sum of the average stock of instruments of each item and the minimum stock.
Depending on the industry affiliation and the scale of production, the transport sector may include various divisions: the transport department, workshops and sections of railway, automobile, electric car and conveyor transport, etc. In individual enterprises, especially small ones, all functions related to intra-factory movement cargo can be carried out by a transport workshop (section) or an individual worker. The scale and structure of the enterprise's transport economy are assessed by cargo turnover, i.e. the number of cargo arriving, shipped and moved within the enterprise. The volume and nature of cargo turnover determine the volume of loading and unloading operations, methods of their mechanization and the necessary front of unloading and loading.
Data on the average daily turnover of wagons are the basis for calculating the size of the unloading and loading front.
The energy sector includes energy networks, facilities and points of energy consumption. At large diversified enterprises, the energy sector covers heat and power stations, compressor and pumping stations, external power grids and other power structures. The main objectives of organizing the energy sector are:
uninterrupted supply of the enterprise with all types of energy;
rational operation of power equipment, its maintenance and repair;
saving fuel and energy resources.
The purpose of the warehouse is to store the necessary reserves of materials, raw materials, fuel, semi-finished products and finished products, ensuring the uninterrupted and rhythmic operation of the enterprise and the safety of materials.
5. Flexible manufacturing systems
A flexible production system (FPS) is a separate unit of technological equipment or a set of such units, as well as systems for ensuring their functioning in automatic mode. A flexible production system has the property of automated changeover when producing products of the production range within the technical capabilities of the process equipment. According to the organizational structure of production, flexible production systems are divided into five levels.
The first level is flexible manufacturing modules (FPM), which are the basis of flexible production. This is a GPS, consisting of a unit of technological equipment, equipped with an automated program control device based on a microprocessor micro- or mini-computer, as well as means of process automation, operating autonomously and having the ability to be integrated into a higher-level system. With a modular production structure, the GPS, in addition to the processing component of the technological equipment, includes a number of other flexible modules:
flexible storage module (FSM) - a set of equipment designed for automated loading, storage, unloading of workpieces, products, etc.;
flexible transport module (GTM) - a set of equipment designed for automated transportation of workpieces, products, etc.;
flexible control and measuring module (GCM) - designed for automated quality control of operations performed;
flexible auxiliary module (GVM) - designed for automated performance of auxiliary operations;
flexible diagnostic module (GDM) - production diagnostics, and sometimes fault finding of the GPS.
Each of the listed modules operates according to the program of an automated flexible module control system.
The second level is a flexible automated line (GAL). This is a flexible production system consisting of several flexible production modules integrated by an automated control system.
The third level is a flexible automated section (GAU). This is a flexible production system, consisting of several flexible production modules, integrated by automated control systems, operating along a technological route and providing the ability to change the sequence of use of process equipment.
The fourth level is a flexible automated workshop (GAS). This is a flexible production system in the form of a set of flexible automated lines or sections, designed for the manufacture of products of a given range.
The fifth level is a flexible automated plant (GAZ). This is a flexible production system, which is a set of flexible automated workshops and is intended for the production of finished products. A flexible automated plant may include separately functioning non-automated sections and workshops.
According to the degree of automation, gas production systems are divided into flexible production complexes and flexible automated production. A flexible production complex (FPC) is a flexible production system consisting of several flexible production modules, united by an automated FPS control system and an automated transport and warehouse system (ATSS), operating autonomously for a given time and having the ability to be integrated into a higher-level system. Flexible automated production (FAP) is a flexible production system consisting of one or more GPC, united by an automated production control system and an automated transport and warehouse system, making an automated transition to the production of new products using a computer-aided design (CAD) system, an automated scientific research system (ASNI) ), automated system for technological preparation of production (ASTPP).
Flexible manufacturing systems can reduce production cycle times by 30 times. The equipment replacement rate increases to 2.5-2.7. Savings in production space reaches 30-40%.
Bibliography
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Production organization method- this is a method of carrying out the production process, which is a set of means and techniques for its implementation. The production organization method is characterized by a number of features, the main of which are the relationship between the sequence of operations of the technological process and the order of equipment placement and the degree of continuity of the production process. There are three methods of organizing production: non-flow, flow, automated.
The non-flow method of organizing production is characterized by the following features:
1) all workplaces are located in similar groups of equipment without any specific connection with the sequence of operations;
2) various objects of labor are processed at workplaces;
3) technological equipment is mainly universal, but for processing parts that are particularly complex in design;
4) parts are moved during the manufacturing process along complex routes, which causes large interruptions in processing due to waiting for them in intermediate warehouses and in subdivisions of the technical control department (QCD).
The non-flow method is used mainly in single and small-scale production and is typical for mechanical repair and experimental shops, small-scale production shops, etc. Non-flow production is organizationally complex.
The main production of processing industry enterprises for the storage and processing of agricultural raw materials is characterized by the widespread use of flow methods. The predominant part of agricultural raw materials at processing enterprises in almost all industries is received and processed in the stream. Therefore, the organization of main production at processing enterprises comes down primarily to the organization of continuous production.
Production flow- This is a special method of organizing production. It is characterized by a number of specific features.
The main ones are the following:
I) dividing the overall process of producing a product into separate component parts - operations;
2) assignment of each operation to a separate workplace, machine and, as a result, repetition of the same labor processes, that is, their clear specialization;
3) simultaneous, parallel execution at workplaces of operations that make up the production process of certain products;
4) arrangement of machines, groups of similar equipment and workplaces in the order of the sequence of individual operations during the production process.
If all the listed signs are present, we can say that in this case there is a production flow in one form or another. The highest forms of continuous production are characterized by a number of additional features: continuity and strictly regulated rhythm of production; immediate transfer of raw materials after completion of processing from one operation to another, synchronization of operations: narrow specialization of jobs and machines; use of specialized technological and transport equipment.
The main structural unit of continuous production is production line. It consists of a series of interconnected workstations and machines arranged in the sequence of individual operations. A production line combines production operations that make up either a completed stage or the entire main process of manufacturing finished products. In the chain of machines (workstations) included in the production line, a leading machine (workstation) must be allocated. It is commonly understood as a machine whose productivity determines the output of the entire production line.
It is necessary to distinguish between main and auxiliary production lines. In a simple line, one workstation or one machine is provided to perform each operation; in a complex line, some operations are performed on several workstations or machines.
The main flow line, unlike the auxiliary ones, includes machines (workstations) that complete the process of converting raw materials into the finished product. Auxiliary lines can relate to both the preparatory and final stages of production.
The production line unites several workplaces connected to each other by various transport devices.
They are divided into several groups:
Continuous transport equipment (belt and scraper conveyors, horizontal and inclined augers, elevators);
Periodic (cyclic) vehicles (forklifts, electric carts);
Non-powered (gravity) transport devices;
Descents, slopes, gravity pipes;
Pneumatic transport.
Conveyors are divided into working and distribution. On working conveyors, not only the object of labor is transported, but also technological operations are performed. They can be with continuous or pulsating movement. In the latter case, the conveyors are automatically turned off while technological operations are performed, and then turned on again to move semi-finished products to the next operations.
Distribution conveyors are intended only for interoperational movement of semi-finished products. They can transfer products to one or a group of workstations. Group transfer is carried out in a strict order, to a specific address.
The automated method refers to a process in which the operations of a technical process are performed by machines and are carried out without the direct participation of a worker. The worker retains only the functions of adjustment, supervision and control. Automation of the production process is achieved through the use of automatic machine systems, which are a combination of heterogeneous equipment located in a technological sequence and combined by means of transportation, control and management to carry out partial processes of product production. There are four main areas of automation.
The first is the introduction of semi-automatic and automatic machines, such as CNC machines. The use of CNC machines allows you to increase labor productivity at each workplace by 3-4 times.
The second direction is the creation of complex machine systems with automation of all parts of the production process. An example is an automatic line (AL), which is the combination into a single production unit of a system of automatic machines with automatic mechanisms and devices for transportation, control, stock accumulation, waste removal, and management.
The efficiency limits of automatic rotary lines (ARL), which are a type of automatic lines equipped with special equipment based on rotary machines and transport devices, are much wider. In the rotating cylinder - rotor, as many nests are made as the number of operations required according to the technology to completely manufacture the part. Rotating the socket with the part in a circle means completing one operation and moving on to the next.
The third direction is the use of industrial robots that perform functions in the production process similar to the human hand, replacing human movements. An example is robotic systems (RTC) for performing various jobs.
The fourth direction is the development of computerization and flexibility of production and technology. The need for the development of flexible production automation is determined by increased international competition, requiring rapid development and updating of products. Production flexibility refers to its ability to quickly and at minimal cost switch to the production of new products using the same equipment. The basis of flexible manufacturing systems (FMS) is the flexible manufacturing module (FMU). GPS, being the highest form of automation, includes in various combinations equipment with CNC, RTK, GPM and various systems for ensuring their functioning.
Method organization of production - This is a certain way of performing the production process, which provides a set of relevant activities and methods for its implementation. For the production organization method, the relationship between the sequence of operations of the technological process and the order of equipment placement and the degree of continuity of the production process is especially important. There are three methods of organizing production:
non-flow (single);
in-line;
automated.
Non-line production characteristic signs are:
at workplaces, objects of labor of different design and manufacturing technology are processed, because their quantity is small and insufficient for normal loading of equipment;
workplaces are located behind the same type of technological groups without a specific connection with the sequence of operations;
objects of labor are moved during processing along complex routes, which causes long breaks between operations.
The technological equipment is basically universal, although when processing parts that are particularly complex in design and large in size, other equipment can be used.
Non-flow method It is used mainly in single and serial production. Depending on the range of products and their quantity, the non-flow method may have different modifications :
under conditions of single production it is carried out mainly in the form single-technological method, when individual items of labor are processed in units or small batches that are not repeated;
in mass production it takes shape party-technological or subject-group method.
Batch-technological method characterized by the fact that objects of labor are processed in batches that are periodically repeated.
The batch size of the items being processed affects production efficiency. Therefore, it is very important to determine the size of the optimal batch. Optimal is such a batch of items , when the total cost of its production is minimal.
Subject-group method lies in the fact that the entire set of objects of labor is distributed into technologically similar groups. The processing of items in each group is carried out using approximately the same technology and requires the same equipment. This makes it possible to create specialized areas for processing subject-specific items, and to increase the level of mechanization and automation of production. Subject-group methods create the prerequisites for the transition to continuous production.
Number of equipment in non-line production is calculated separately for each group of similar, technologically interchangeable machines:
, Where
KM - number of machines (machines) in a technological group;
P- the number of items that are processed on this equipment;
N 1 - the number of items of the ith name that are processed during the billing period;
tі - standard time for processing the i-th item, year;
Tr - planned fund of operating time of a piece of equipment for the billing period, year;
Kn- coefficient of fulfillment of time standards.
Line production – a highly effective method of organizing the production process, which involves processing items of labor along a set shortest route with a fixed time.
The main feature of continuous production is a stable range of launching homogeneous products. In continuous production, the basic principles of highly efficient organization of the production process and, above all, the principles of continuity are most fully expressed. Flow methods are used in conditions of manufacturing significant volumes of products over a long period of time, mainly in mass and large-scale production.
Line production is the highest form of implementation of mass production with the following characteristic features:
dividing the technological process into specific operations and assigning them to specific jobs;
precisely defined duration (synchronism) of operations;
placement of workplaces in the sequence of the technological process of manufacturing a product (subject placement principle);
equipment of lines, for the most part, with transport devices (conveyors, pneumatic conveyors, industrial work, manipulators, etc.), which are designed to transfer products from one workplace to another, as well as to regulate the rhythm of the production line.
The main structural unit of continuous production is production line - a technologically and organizationally separated group of workplaces at which one or more similar standard sizes of products are manufactured. Production lines are different, because they are classify Bycertain signs :
By the number of items manufactured on them:
single-subject (continuous-flow);
multi-subject (multi-threaded).
By the nature of the movement of products through operations:
continuous-flow;
discontinuous-flow.
According to the method of maintaining rhythm:
with a regulated rhythm;
with free rhythm.
By type of vehicle use:
conveyor;
not conveyor.
According to the nature of the conveyor movement:
continuous action;
periodic action.
By location of operations:
on the conveyor;
at specially equipped workplaces.
For efficient operation of the enterprise, a certain type of production line is selected and its main parameters are calculated: tact, pace, rhythm, number of jobs, conveyor speed and length of working zones.
Production line clock – this is the time interval during which products leave the line and move sequentially one after another, that is, this is the time interval through which certain products are periodically released:
V= , Where
V- conveyor speed, m/min;
l- distance between the centers of two adjacent workplaces (products on a conveyor), m.
On a working conveyor with continuous movement, when performing an operation, the pendulum moves along the conveyor within the limits of the work assigned to it. At the end of the operation, the worker returns to the beginning of the zone and performs the operation on the next product, which at that moment has approached the work zone.
Working area length calculated by the formula:
t=
,
Where
T- production line cycle, min;
Teff - effective operating time of the production line in the planning period, min;
IN p l - the reciprocal of the clock cycle is called production line rate (T) and is calculated by the formula:
T=
.
The production line rate, which expresses the number of products that will leave the production line (conveyor) in one hour of its operation, is determined by the formula:
T=
.
If objects of labor are transferred not individually, but in transport batches (Fri), then they leave the line during a time interval called rhythm of the line , which is determined by the formula:
R= r X Fri,Where
R- line rhythm, min.
Number of workplaces is calculated for each operation using the formula:
RM і =, Where
RMi - estimated number of jobs at the i-th operation.
Conveyor speed depends on its tact and the distance between the products (or the centers of two adjacent workplaces):
РЗ=lX, Where
RZ - length of the working area at the i-th operation, m.
Flow production has some disadvantages, namely:
monotony and monotony of work;
sensitivity to possible deviations in supplies, equipment and documentation, which may lead to a shutdown of the conveyor.
To solve these problems of continuous production, automatic production lines were characteristic.
Automatic production lines - This is a set of machines that automatically, with human participation, perform specified technological operations, including transportation, quality control, and the like.
Hence, production automation - a process in which all or most of the operations that require the physical efforts of a worker are transferred to machines and occur without his direct participation. The worker has only the function of establishing, supervising and controlling.
Each type of production corresponds to certain methods of its organization.
Production organization method- a set of methods, techniques and rules for the rational combination of the main elements of the production process in space and time.
Its main characteristics include:
The relationship between the sequence of technological process operations and the order of equipment placement;
The degree of continuity of the production process.
Products manufactured at enterprises can be divided into two types: discrete(consisting of different parts, for example, machines, instruments, receivers, televisions, computers, etc.) and indivisible(which cannot be divided into parts or components, for example, liquid substances, metals, metal alloys, varnishes, paints, etc.).
For the production of discrete products can be used intermittent(discrete) and conditionally continuous production processes, and for the production of indivisible products only continuous processes.
All products manufactured at mechanical engineering enterprises are discrete, and production processes are divided into discontinuous and semi-continuous, which are as close as possible to continuity in discrete production conditions.
There are three methods of organizing production processes: non-flow (operational), flow and automated.
Non-flow (operational) method production organization is used mainly in single and small-scale production. It is characterized by the following features:
Production equipment is grouped based on the work performed (process);
The technological equipment is mostly universal. At the same time, special equipment is used to process particularly precise parts;
Between groups of technological equipment, as a rule, there are intermediate warehouses and workplaces for quality control inspectors;
Parts during the manufacturing process are moved from one operation to another along complex routes, so there are long interruptions in the technological process.
In non-line production, as a rule, the development of technological processes is of an individual nature.
Disadvantages of non-line production:
1. low production efficiency;
2. production is organizationally complex.
Non-line production can be implemented in technological, subject and mixed forms.
In-line method production organization is used for mass, large- and medium-scale production of products. It is characterized by the fact that the object of labor during processing follows the established shortest route without waiting at intermediate warehouses and workplaces of quality control inspectors. This is the most advanced method of organizing production in terms of clarity and completeness.
The characteristics of the flow method of organizing production include:
Dividing the production process into separate operations and assigning them to a specific workplace for a long time;
Specialization of each worker to perform a certain operation;
Coordination and rhythmic execution of all operations at all workplaces based on a single calculated clock cycle (rhythm) of the production line;
Placement of workplaces in strict accordance with the sequence of the technological process;
Moving objects of labor from one workplace to another with minimal interruption and using special vehicles.
This method is based on the principles of rational organization of production - direct flow, continuity and rhythm.
The main organizing element of continuous production is production line. It is a set of specialized workplaces located in accordance with the technological process.
Production lines are classified according to certain characteristics.
By nomenclature processed products are distinguished:
Single-item production lines (typical for mass production, they are assigned for a long time to the processing or assembly of one product item);
Multi-subject (typical for mass production; they can process several items of products that are structurally and technologically similar).
By degrees of continuity production lines distinguish the following:
Continuous-flow (provides strict rhythm and the shortest production cycle);
Discontinuous-flow (they do not provide for clear synchronization of operations at workplaces.
The choice of methods for organizing flow and non-flow production is influenced by various factors, these include:
Dimensions and weight of the product: the larger the product and the greater its weight, the more difficult it is to organize continuous production;
The number of products to be produced over a certain period of time (year, quarter, month, day): when producing a small number of products, as a rule, it is inappropriate to organize mass production (capital costs are too high);
Frequency of product release: with regular (rhythmic) production, it is advisable to organize continuous production, and if the regularity is uncertain or at different periods of time and in different quantities, then it is necessary to use non-line production methods;
Machining accuracy and surface roughness of parts: for high precision and low roughness, non-linear methods should be used.
Automated production- a production process in which all or the vast majority of operations requiring physical effort are performed by machines without direct human intervention. The workers perform only adjustment and control functions.
Automation of the production process is achieved through the use of automatic machine systems, which are a combination of various equipment and other technical devices located in a technological sequence and combined by means of transportation, control and management to carry out partial processes of product production.
