The production cycle and methods of organization of production
For the successful work of the enterprise it’s necessary to rationally form the structure of production and organization. The most important element of the production is the production cycle, on the basis of which production capacity is calculated, the volume of work in progress is determined, the launch dates of the products are set and other calculations for planning and production are carried out. Useful methods of organizing the production process can be divided into three types.
The production process is a set of actions of employees, by which raw materials are converted into finished products. The type of production is determined also by such components of the production process, such as:
- Professional staff;
- Work equipment (machinery, buildings, tools);
- Objects of labor (raw materials);
- Energy (electricity, thermal energy, mechanical energy, light energy, muscle power);
- Information (legal, political, commercial, industrial).
The production cycle is one of the most important technical and economic indicators, a calendar period of time from the start of the processing of raw materials to the end of production of the finished product. The production cycle includes primary and secondary manufacturing operations, as well as interruptions in the manufacturing process of products.
The technological cycle is the time of performance of basic technological operations. During the technological cycle a worker or the mechanisms he operates have a direct impact on the subject of work. Also the technological cycle includes production processes conducted without people and equipment, such as drying or cooling of products in the air.
The calculation of the duration of the production cycle is made according to the formula
Тc = Тm + Тa + Тb,
Where Tm is the time of execution of major operations; Тa - the time of execution of auxiliary operations; Тb – time of the breaks.
Reduction of the time of the production cycle is the most important source of increasing production efficiency at the enterprise. The shorter production cycle is, the better the productive capacity of the enterprise is used. In addition, short production cycle helps to reduce the volume of work in progress and reduce production costs.
The length of the production cycle is affected by the complexity of manufacturing products, the level of applied technologies, mechanization and automation of manufacturing operations, operating mode of the enterprise, uninterrupted supply of working materials and tools, as well as energy.
The length of the production cycle is also affected by the type of combination of process steps and the order of transfer of the object of labor from one workplace to another.
There are three kinds of combinations of technological operations:
- Serial;
- Parallel;
- Parallel-serial.
During the serial movement the processing of the kit of details at the transition to each subsequent operation starts after the processing of all party during the previous operation.
In case of parallel movement transfer of the details to the subsequent operation is carried out one by one or by transport party immediately after processing during the previous operation.
Parallel order of operations ensures the shortest production cycle, but because of the unequal duration of individual operations downtime of workers and equipment occurs. Thus, this method of work is not always rational. In this case, preference can be given to a parallel-serial combination of operations, when the details are transferred from one operation to another by transport or individually, and the whole party is processed during each operation without interruption. In case of parallel-serial type of motion the production cycle of the details lasts longer than in case of parallel motion, but considerably less than in case of series motion.
Used methods of organizing the production process can be divided into three types:
- In-line;
- By parties;
- By units.
Characteristics of the line method:
- Division of the production process into individual operations;
- A clear specialization of workplaces;
- Parallel execution of the operations on the workplaces;
- The location of the equipment along the production process;
- Continuity of the production process, which is achieved due to the equality or multiplicity of the duration of the operations to the time of the workflow. (Cycle is the time between the launch or the release of two related products on the production line. The value reverse to cycle is the rhythm of the production line.);
- Special vehicles for the transfer of objects of labor from one operation to another.
The basic tructural unit of mass production is a production line. This is a set of work places located along the technological process and interconnected by special means of transport. The most commonly used transport vehicles are conveyors. On the conveyors of continuous processing the operations are carried out during the movement of the product. When the nature of the work is pulsating the conveyor is stopped for the duration of the operations. Production lines are most common in light and food industries, mechanical engineering, metal processing and other industries.
Line method of organizing the production process is characterized by high efficiency, which is achieved due to the high level of use of all the principles of the organization of production.
Manifestations of efficiency of the line method:
- Increased productivity;
- Mechanization of the production process;
- Narrow specialization of jobs;
- Reduction of the processing cycle;
- Reduction of the production costs.
Disadvantages of line organization of the production process:
- Increased turnover because of repetitive work on conveyors;
- The need to complete the preparation of products for production: any revision requires stopping all the conveyor;
- Stopping the entire production line because of a failure of the machine or the absence of the worker.
Characteristics of the batchwise method of the organization of production:
- Launch of products into production by batches;
- Simultaneous processing of several types of products;
- Performing multiple operations at the same workplace;
- Use of specialized and universal equipment;
- Attracting skilled workers of broad specialization;
- Location of equipment by groups of similar machines.
Most of all batchwise methods of organizing the production are used in series and small batch production, in procurement departments and mass volume production, which uses high-performance equipment the capacity of which overcomes the capacity of the machines in the following departments.
The method of organizing the production by units is used in the manufacture of products in single units or small non-recurring batches. It is used in the manufacture of complex unique equipment (rolling mills, turbines, etc.), special equipment, when performing certain types of repairs.
Characteristics of the method of organizing the production by units:
- Non-recurring product range;
- Use of special and universal equipment;
- Location of equipment in groups of similar machines;
- Attracting skilled workers of broad specialization;
- A large number of works with the use of manual labor;
- Large stocks of work in progress;
- High costs of production and sales;
- Low turnover of the working capital.
Improvement of the efficiency of a “by units” method of organizing the production is possible thanks to the development of standardization and unification of parts and components, the use of group processing methods.
