Judging capability of processes

Each time I go through the topic of process capability, I get a few interesting questions. Some of them are...
- What is the difference between Cp, Cpk?
- Why is Cpk of 1.33 critical? What does this value tell about my process?
- What index would apply for one sided tolerances?
- There are so many indices, which is the most appropriate index for my process?

For more information on capability indices, please read our White Paper Use of different capability indices.

Most customers today are demanding specific capability indices be reported with product shipped. Some suppliers wonder why this information is so important.

Customers want to know the suppliers process capability. Using the capability indices, customers can judge the capability of the process for producing parts that are consistently within specifications. This gives customers some confidence about the parts supplied.