00317 §8ddf873a508f535a2304aca8bc776b

320

McCarville & Montgomery

units will be rejected due to gage error can be found. This can be seen in FigurÄ™ 6. Again, by using the equality shown in Equation (6) and by summing up the units from negative infinity to the guard band chosen, the total Ä…uantity of good units thrown away by the gage can be calculated as follows:

USL z

P(reject)good) = J[fU)/g'(y)dy)dz    (?)

•tC    -CO

So, Information leamed from product and gage capability studies no longer ends with the P/T ratio or the acceptability of the gage, but can be utilized in determining the defect levels as well as the yield loss caused by the gage error as described in EÄ…uations (5) and (7).

FigurÄ™ 6. The Probability of Having Some Good Units and the Associated Probability of Those Good Units Being Rejected by the Gage.