Process planning is a staff activity. It may constitute a department or alternatively may be considered a subgroup which, along with other subgroups such as plant layout, tool design, etc., will make up a manufacturing staff or manufacturing services department.
Procedure of Designing a Manufacturing Process
The following steps are involved in the design of a manufacturing process:
1. Product Design
Designing a process begins with the consideration or a careful review of the product design and specifications to ensure that economical manufacturing is feasible. The product engineer and the process planner should collaborate on the design of the product to make sure that realistic specifications are set and the product is designed to permit the use of the most economical method.
2. Material List
All the materials and parts that will be used are listed. The standard quantity of each item that will be required for manufacturing one unit of final product should be determined. A bill of materials to be bought from outside.
3. Sequence of Operations
The labour operations to be performed on each component and their sequences (order) are decided. The sequence should be such that it will permit the desired rate and quality of output at the optimum manufacturing cost. The process engineer must be well experienced in methods and tool design so that the most appropriate sequence of operations can be selected. The method selected must ensure optimization of cost.
4. Tool Design
The machines, equipment and tools most appropriate for the product and volume of output are then designed. Machine setting e.g., speed, feed temperature, pressure, etc., are also decided at this stage. If a finished product is made up of a large number of components or parts, the sub-assemblies and final assembly are determined to simplify control and to minimize costs.
The layout of production, installation of manufacturing facilities and auxiliary service is decided. Related operations should be effectively integrated. The grouping of equipment and their proximity to each other would depend upon the volume of production and available production facilities. Close integration of operations makes plant layout compact and reduces time and cost of processing materials. However, it may reduce flexibility of the manufacturing process.
6. Control System
Necessary control of materials, machines and manpower is established to ensure effective utilization of the manufacturing facilities and most economical production of the product.
The above steps or elements of process designing are usually known as Production engineering or Process engineering or Tool engineering. The scope of process planning includes all work that is necessary to ensure manufacture of the product by the most economical means.