Warranty Claims Reduction

148 • Warranty Claims Reduction

corrective action to produce immediate results, run the process to make a

sucient number of pieces so that you can reasonably expect the correc-

tive action to have taken eect, and then start taking the samples for eec-

tiveness verication. Count or measure whatever characteristic you need

to measure to verify the corrective action is eective. For subtle changes

or data that are highly variable, it may be necessary to perform a statistical

test of signicant dierence, like the sign test or a t- test, to prove whether

or not the corrective action is actually eective.

Aer the successful implementation of the corrective action, wait a

few days and see how things are going. Talk with the operators about the ...