Gage RR – a validating mould and part must have….

Hands up I have done this a few times validated a mould tool without requesting a GAGE RR to be performed prior to receiving the measurement data back to enable to truly understand mould process capability or DOE results. Of course there’s been ‘gauges’ available to use, but unless I saw the GAGE RR result I didn’t really know how accurate these are, how they can be relied upon to give repeatable results…. how robust was my gauge am working with and how good was my operator using the gauge.. You would be surprised when dealing with small tolerance parts how much variation can be attributed to the gauge or operator. The standard criteria for accepting a gauge is 1.33 criteria. I have however known pass criteria of <30% but at Plazology we prefer to be working in the lower regions… and so do our customers… Repeat and reproduce is the aim of the study using the same person measuring the same parts a number of times using the same gauge… by adding in the second or third operator allows you to understand how well the values are reproduced. If you are finding the results are giving you values over the 10% pass criteria than this could contribute to higher than required spread and intern have a negative effect on reviewing process capability. If this is the case investigate into the reasons behind the higher value. Sometimes not having wide enough spread of parts to cover the tolerance range will give poor results also… We find using Minitab 17 gives us a nice summary results page using both numerical & graphical ways for reporting Gage RR, highlighting the areas to focus in on to improve the results… theirs also standard excel formulas which can be used to give just as good results but when writing up validation reports sometimes pictures can explain results better than words…