In intermittent production, the basic product design changes from time to time. Therefore, facilities should be flexible enough to handle a wide variety of products and of different shapes and size. Production facilities are arranged according to their functions so that functional skills and expertise can be concentrated on a specialized operation. Intermittent Production may be of two types : (1) Job production; and (2) Batch production. Here, we have discussed only Job production system. For Batch production system another article is presented for your understanding.
1. Job or unit production : It involves the manufacturing of a single complete unit with the use of a group of operators and processes as per the customer’s order. This is a ‘special order’ type of production. Each job or product is different from the others and no repetition is involved. The whole job is one operation and work is completed separately on each job. The product is usually costly and non-standardized. There is absence of identical jobs and long runs on a single job. Jobs are carried out to the customers’ specifications. Thus, job production consists of “the bringing together of materials, parts and components in order to assemble and commission a single piece of equipment or product.”
Under job production, goods are produced to specific customer orders. Customers do not make demand for exactly the same product on a continuing basis and, therefore, production becomes intermittent. Each Product is a class by itself and constitutes a separate job for production purposes. Ship building, electric power plant, furnace making, dams construction, jobbing functions, machine shops, printing press are common examples of job production. Firms engaged in subcontract, work such as tool making, machining, sheet-metal work and sub-assembly, use job production system.
Characteristics of Job Production System
Characteristics : The main characteristics of job production art as follows :
(i) The product manufactured is custom-made or non-standardized.
(ii). Machines and equipment are waned or assembled at one place, i.e., fixed position layout is used.
(iii) A wide range of general purpose machines like grinder, drill press, sharper, etc., is used.
(iv) Volume of output is generally small
(v) Variable path materials handling equipment are used.
Advantages of Job Production System:
Job production involves comparatively small investment in machinery and equipment. It is flexible and can be adapted easily to changes in product design. A fault in one operation does not result into complete stoppage of the entire process.
Disadvantages of Job Production System:
Job shop manufacturing is the most complex system of production. For instance, in building a ship thousands of individual parts must be fabricated and assembled. A complex schedule of activities is required to ensure smooth flow of work without any bottlenecks. Many parts require operation time on the same machines even though the operations in the manufacturing cycle take place at different points of time. Optimum machine loading is, therefore, a very difficult problem.
Raw materials and work-in-progress inventories are high due to uneven and irregular flow of work. Therefore, large storage space is required and material handling costs are high. Highly skilled machine operators are required for the efficient performance of setting up and operating tasks. Work loads are unbalanced. Labor and equipment must be flexible to accommodate the continuously changing production. There is often inefficient utilization of labor and plant. Speed of work is slow and unit costs are high.
Thus, job shop production is applicable where custom-made products are to be produced on a small scale.