Dear friends,
If may choosen parts for R&R study is having with in job variation (ovality, taper) what is should I do, whether I have to mark a position and ensure the gage R&R in that perticular zone are just I can go with this variations. Pl. advise

:agree:

Welcome to the cove,

We have to evaluate the study by looking on each variation whether it is repeatability, reproducebility, part and operator interaction and part.

From there we may conduct the 5 why analysis to detemine the root cause.

The whole idea for the measurement system analysis is to reduce the measurement variation in term of accuracy and precision and ensure the observe variation is come from the actual process variation.

Is the gage or device used for inspection or process control?
Use the P/T ratio for inspection in purpose and study variation for process control in purpose.

Thank You Mr Yew jin,
I think I have got your point i.e. the selected gage or device for measurement should be able to give the clear / exact value of the part quality with all the variations. Pl. correct if my understanding is wrong.

Dear friends,
If may choosen parts for R&R study is having with in job variation (ovality, taper) what is should I do, whether I have to mark a position and ensure the gage R&R in that perticular zone are just I can go with this variations. Pl. advise

:agree:

The with-in part variation in form (e.g., ovality and taper) will show up in Repeatability.

Ideally, you use a gage that can demonstrate repeatability despite this variation in form. However, many times you cannot find such a gage. When this occurs, you must proceduralize a method that will provide this repeatability. This procedure may consist of taking the maximum measurement, the minimum, the average of both, the diameter at a specified distance from the end (for taper), etc.

You must find a method that provides repeatable results and makes sense in the application. For example, if the feature is a tapered hole that must pass a locating pin, you should probably use the minimum diameter.

Marking the location for the next measurement does not make sense unless it is to locate the point at a specified distance because the first, and possibly only, person to measure the feature will not have such a mark to guide them.