Process Capability Introduction (SPC Introduction)-Process capability improvement and evaluation

How to improve the process capability

Refer to the following normal distribution map, the original production capacity is insufficient, the finished product has a certain ratio beyond the lower limit, and its improvement strategy has two:

1. Reduce the variation of the process, that is, improve Cp, increase the value of Cp .
2. Move the process center, that is, to improve the CK, minus the value of CK .

On the technical side, in order to reduce the variation of the process, that is, the change in precision, often means that the need to purchase new manufacturing equipment to improve the machine size error, or require a more precise part size specification, to the finished product precision improvement. Generally speaking, as long as the location of the relative size of the machine is improved, or the method of the assembly is improved, the purpose of moving the process center can be achieved, and then with the control of the use of the map, the control of the size of the machine or the method, you can achieve the product yield of the maintenance.

So, moving the process center is a little more variable than shrinking the manufacturing process. If the simple process center moves, the yield of the finished product can be improved, and the average person will use this method first.

Image evaluation of the process capability

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Process Capability Introduction (SPC Introduction)-Process capability improvement and evaluation