Operation Classifications and the Process Sequence

One must understand the various operations involved and how they must fit together in producing a product in order to obtain complete idea about the manufacturing sequence. The diagram in Figure 10 shows how different operations can be fitted together into a complete sequence.

The material received from basic process, may be associated with one or more of principal operations. For example, if the material received is forging or casting, it must be completed by a cutting type operation. Thus, cutting becomes the principal process, to follow. If the material from the basic process operation is in the form of pig iron, then casting becomes the principal process of manufacture.

A diagram in this case is constructed to show cutting as the principal process operation and a operation sequence chart is developed, it is supplemented by various auxiliary and supporting operations. The termination of the major process operations are packaging and shipping. If the part were to become a part of an assembly as a continuation of the manufacturing process, then assembly would become a principal process operation and an assembly process chart is developed to depict the details of all the activities involved.