In intermittent production system, basic product design changes from period to period. As a result, facilities need to be flexible enough to handle a wide variety of products and their different shapes and sizes. Production facilities are arranged in accordance with their functions so that the functional skills and expertise can be concentrated on a specialized operation. Intermittent Production system may be of two types : (1) Job production; and (2) Batch production. Here, we have discussed only Batch production system. For Job production system another article is presented for your understanding.
2. Batch production system : It has been defined as “the manufacture of a product in small or large batches or lots at intervals by a series of operations, each operation being carried out on the whole batch before any subsequent operation is performed.”‘ In this type of production, the work on any product is divided into few operations and each operation is completed for the whole lot before proceeding to the next operation. Each batch contains identical items but every batch is different from the others. A fixed quantity or batch rather than continuous supply is required. A particular operation on a batch is performed by one group and then it is passed on to other groups for subsequent operations.
For example, the printing operation may be done by one group, the jobbing work by another, and so on. Generally, one group completes the operation on the whole lot before it is passed on to the next group for subsequent operation and a part of the lot is not transferred. Thus, batch production is a mixture of mass production and job production. Under it, machines turn out different products at intervals, each product being produced for comparatively short time using mass methods.
Industrial blowers, electric Motors, book printing, export production, machine tools are usually done by batch system. In batch production, machines and other facilities become available for the production of another batch after the production of a particular batch is completed. Both job production and batch production are similar in nature except that in batch production the quantity of product manufactured is comparatively large.
Characteristics of Batch Production System:
The essential features of batch production are given below :
(i) A large variety of products are manufactured in lots or batches.
(ii) Both general purpose machines (for producing parts) and special purpose machines (for assembling the parts) are used.
(iii) Variable path materials handling equipment is used.
(iv) Machines and equipment are arranged according to the sequence of operations, i.e., process layout is used.
Advantages and Disadvantages of Batch Production System:
Batch production combines the features of both flow production and job production types. Some degree of specialization is possible and capital investment is comparatively low. But work-in-progress inventory is high and large storage space is required. Due to frequent changes in product design no standard sequence of operations can be used. Machine set-ups and tooling arrangements have to be changed frequently.
The main problem in batch production is the idle time between one operation and the other. The work has to wait until a particular operation is carried out on the whole batch. For example, assume that a particular batch is processed through four stages.
The first unit of a batch undergoes the first operation within one week but it has to wait until four weeks when the first operation on the whole batch will be completed. Similarly, after each operation waiting or rest time is involved. Such delay results in substantial work-in-progress and considerable time lag in production. As a result investment is high and return on capital employed is low. Sometimes, a buffer stock may have to be maintained in order to ensure operating flexibility and effective use of resources. A proper balance must be arrived at between investment in material and investment in other resources.
Suitability of Batch Production System:
Batch production is applied when either the volume of output increases resulting in some repetitiveness or the market demand is not uniform throughout the year. In the latter case occasional discontinuity in production occurs as switching to other product becomes necessary.