Process planning and process design

At the time of designing a product, preliminary consideration is given to the capacity of the firm to manufacture the product. The technology required and the particular machines and processes needed are determined and compared to what is available in the firm. If production is compatible with the existing manufacturing capacity or if the needed capacity can be acquired ,the decision is taken to continue designing the product .If not, the decision may be to terminate the design effort.

After the final design of the product has been completed, process planning and process design must be taken up .As the process plans are firmly established, the processing time requirements of specific machinery and equipment are generated. These processing time requirements must be evaluated against available capacity and against the cost of acquiring the new machines and equipments required before a final decision is made to produce the product.

Process Planning

Process planning is concerned with planning the conversion or transformation processes needed to convert the materials into finished products .A production process is a series of manufacturing operations performed at workstations to achieve the design specifications of the planned output .A vast number of different operations and various kinds of equipments and machines may be required to produce a complex product (for e.g. an aircraft or a ship). Simpler parts may require fewer operations (for e.g. a bolt and a nut).

Process planning consists of two parts namely

1. Process design
2. Operations design

Both stages provide information on what is required to effectively utilize the existing equipment and machinery and to determine what new equipment and machinery would be required.

Process Design

Process design is concerned with the overall sequence of operations required to achieve the product specifications. It specifies the type of work stations that are to be used, the machines and equipment necessary and the quantities in which each are required.

The sequence of operations in the manufacturing process is determined by

1. The nature of the product
2. The materials used
3. The quantities being produced
4. The existing physical layout of the plant.

Operations Design

Operations design is concerned with the design of the individual manufacturing operations .It consists of examining the man-machine relationship in the manufacturing process for converting the raw materials into the finished or semi-finished product .Operations design must specify how much of man and machine time is required for each unit of production.

Frame Work for Process Design

The design of the transformation process requires answers to several questions given below:

1.What are the characteristics of the product or service being supplied or offered to the customer?

2.What is the expected volume of the output?

3.What kinds of equipment or machinery are available?

4.Should the equipment or machinery be custom built?

5.What is the cost of equipment and machinery needed?

6.What types of labor skills are available, in what quantities and at what wage rates?

7.How much money can be spent on the manufacturing process?

8.Should the process be capital intensive or labor intensive?

9.Should the components or parts be made or purchased ?(Make or buy decision)

10.Which would be the best way to handle the materials?

System Approach to Process Planning and Design

1. Inputs

• Product/service information such as product/service demand, prices/volumes, competitive environment , customer needs/wants and desired product characteristics

• Production system information such as resource availability, production economics, available technologies and technologies that can be acquired and predominant strengths and weakness of the firm.

• Operations strategies, such as positioning strategy, competitive strategy, focus of factory and service facilities and allocation of resources.