Manufacturing involves the conversion of raw materials, usually supplied in simple or shapeless forms, into finished products with specific shape, structure, and properties that fulfill given requirements. This conversion into finished products is accomplished using a great variety of processes that apply energy to produce controlled changes in the configuration properties of materials. The energy applied during processing may be mechanical, thermal, electrical, or chemical in nature. The results are meant to satisfy functional requirements that were defined during the product design stage.
Manufacturing a product or component usually requires the integration of a number of processes. For example, the initial process may involve casting a metal into a mold to produce a desired shape. Next, the casting may be machined with cutting tools to generate surfaces of specified form. Finally, a surface treatment may be employed to improve the durability of the part. Each of these three individual operations—casting, machining, and surface treatment—is a unit manufacturing process. For brevity, in this report they will be referred to as ”unit processes.” They are the individual steps required to produce finished goods by transforming raw material and adding value to the workpiece as it becomes a finished product.