Capability Study - Feasible? Capability Study when there is No Set Target Value

[precabcorp]

We often perform capability studies for our customers on dimensions, but now we are faced with a dilema. One of our customers is asking for a capability study on a measurement that is defined as a range on the print. The print says that any measurement between .33 & .80 is good, without defining a target. We have completed the Gage R&R and the XBAR, R charts succesfully. The problem is we don't know how to do a capability study when there is no set target value. Is this possible.

 

[Don Winton]

Sorry Marc, but I have been away for awhile, for reasons you know. My on-line time has also been reduced, but I will still try to help with some topics when I can. Will be back as soon as I can. Anyway, on with the show.

As far as capability goes, I would suggest precabcorp download and read the cpk.pdf paper I have written and posted. You can find it at Marc's pdf zone.

 

[Batman]

Remember that Cpk or Ppk only cares about how close you are to one tolerance end or the other, not how close you are to the target - that's Cpm. Your tolerance is .33 and .80. What's your capability?