MSA on a process using different fixtures

[suhananyc]

Hi all,

Need some input on my enquiry below


My process is to repair aircraft blades. The blades have different stages (example stage 1-7) and the blade at different stages vary in size. When we measure at different stages we will be using different fixtures. My questions are as below
1) Do I select the parts based on process variation or product tolerance?
2) If I select to do on product tolerance, do I have to do the GRR on all the different stages since different stages uses different fixtures? Or can I just select one range to do and just do a linearity test for the other stages?


Thanks

 

[Bev D]

Well it depends. Does the size at one phase effect the ability of subsequent phases to be completed or measure properly?

Frankly given the importance of the blade to the system I would err on the side of performing an MSA at each stage across the process variation and then you will know the answer to your question. (It's funny but we can rarely debate our way to the answer of a scientific question; We must do the test. Too often we waste more time debating the merits of various approaches - trying to get out of the work - than we would expend if we just did the work)