In the production process, any changes in shape, size, location and nature of the production object, making the finished product or semi-called process. It is the main part of the production process. The process can be divided into casting, forging, stamping, welding, machining, assembly and other processes, precision machining unit instrument manufacturing process generally refers to the sum of the parts assembly process machining processes and machines, other processes are called secondary processes, such as transportation, storage, power supply, equipment maintenance . Process in turn one or several steps arranged in order of composition, by a process consisting of a number of process steps.