process capability?

Question

why do production departments carry out process capability studies?

Answer 1

It's basically to know whether the fluctuation in measurement from part to part is low enough.

When you do quality assurance measurements, you don't want to have to check every single piece.

When you find that the process is "capable" (the standard deviations are low enough), you know you only need to check a small sample of parts to know whether you are within or out of tolerance.

Answer 2

Processes following best practices have been documented to improve productivity and quality by several fold. Crosby, Demmings, the Software Productivity Consortium, Carnegie Mellon's Software Engineering Institute, and others can demonstrate remarkable improvements for each level of process improvement.

Process descriptions are descriptions of what should be done more than how to do them. How entails specifying the tools and other resources used to carry out the processes. That unnecessarily complicates the descriptions; unnecessarily because knowing what to do has more effect on improving productivity and quality than knowing what tools to use.

A major drawback to process improvement is the time, money, and effort that must be invested in that improvement before measurable improvements can be realized. As a consequence, many, if not most, organizations that start out with good intentions to improve their processes never do. They give up too early or put an insufficient amount of investment into their process improvement program.

Answer 3

This is related to statistics. Production departments study the deviation of product specifications from the standards.

Process capability involves study of sigma (standard deviation) for the process. That is, if you are studying the Process Capability of a machine that produces engine cylinders, then you study the diameter of the cylinders. You take all the observed data and calculate the mean and std dev of the readings and draw analysis. The analysis is complex and uses advanced statistical analysis, which is beyond the scope of explaning here.
To give you a hint, you may have heard of 6 sigma, which is related to GE. It is infact, making sure that 99.9999% output stays within the defined limits (standards).

If you really want further information on statistical analysis, you can IM me. But, do not ask for it if you are at school level as it would be too confusing for you at this stage.

Answer 4

To know how much is our capability to obtain the maximum production under the given circumstances.

Answer 5

Good Question