Key decision in process design


New products are not realities until they are manufactured. Process design is necessary to manufacture new products. Process design means the complete delineation and description of specific steps in the production process and the linkages among the steps that will enable the production system to produce the desired quality, in the required quantity, at the time, customers want them and at the budgeted cost.

Key decisions relating to process design relate to organizing the process flows, relating process design to process flow and evaluating the process.

Organizing Process Flows

Five types of process are distinguished. They are:

1. Project.
2. Job shop.
3. Batch assembly.
4. Assembly line.
5. Users of continuous flow technology.

Project deals with one-of- a-kind products that are tailored to the unique requirements of each customer. A construction company, with its many kinds and sizes of projects, is an example. Since the product cannot be standard, the conversion process must be flexible in its equipment capabilities, human skills and procedures. The conversion process features problem-solving, teamwork and coordinated design and production of unique products

Job-shop process is appropriate for manufactures of small batches of different products, each of which is custom designed and, hence, requires its own unique set of processing steps, or routing through the production process. Printing press illustrates job-shop technology. Each product uses only portion of the shop’s human resources and general purpose equipments. With a large number of different jobs, elaborate job-tracking and control systems are used. Much time is spent waiting for access to equipment; some equipment is overloaded while the other equipment is idle, depending upon the mix of jobs at hand.

Batch technology is a step ahead from job-shop process in terms of product standardization, but it is not as standardization as the assembly line process. Within the wide range of products in a batch, several are produced repeatedly and that too in large volumes. These few dominant products differentiate batch facilities from job shops; however, no product is sufficiently dominant to warrant dedicated equipment and process. Consequently, like job shops, batch facilities produce a wide variety of products in a wide variety of volumes. The system must be flexible for the low-volume / high –variety products, but the higher volume product can be processed differently –for example, by producing some batches fro stocking rather than for customer order.

Assembly line (or simply line) technology is for facilities that produce a narrow range of standardized products. Laundry appliances are a representative example. Since the
product designs are relatively stable, specialized equipment, human skills and management systems can be developed and dedicated to the limited range of products and volumes. Beyond this range, the system is rigid.

Users of continuous flow technology are exemplified by chemical plants and oil refineries. Materials and products are produced in continuous, endless flows, rather than in batches of discrete units. The product is highly standardized, as are all of the manufacturing procedures, the sequence of product build-up, materials and equipment. Continuous flow technology affords high-volume, around –the-clock operations with capital –intensive and specialized automation.