GR&R for a Stopwatch used to check a built-in Machine Timer

sinned

Registered Visitor
All,
We are using a stopwatch to check if the build-in machine timer is able to correctly stop the mixing machine at a specific time span setting (tol.=+/-10sec; the mixing time is not a critical parameter affecting the quality of the product). The stopwatch itself has been calibrated for accuracy.

Shall we need to do GR&R ?
 

Ninja

Looking for Reality
Trusted Information Resource
FWIW, I wouldn't.

{and I'd likely smack the guy who told me I had to...}

Using a calibrated stopwatch to gage +/- 10 seconds on a non-critical item...why bother doing the extra paperwork? As long as you don't fall asleep watching the thing, it seems pretty easy.
I'm not even sure I would have bothered calibrating the stopwatch if time is not critical.

HTH
 

Bev D

Heretical Statistician
Leader
Super Moderator
agreed. a gage R&R on the stopwatch is not warranted

as an aside, the largest component of measurement variation with a stopwatch is the reaction time of the user. :cool:
 

Ninja

Looking for Reality
Trusted Information Resource
Says you, I myself have the reflexes of a ninja cat.

Is that NIST traceable?
Have you performed GRR on that?
Is "Ninja Cat" what the 'NC' stands for, ncwalker? I always thought it was non-conforming...:tg:
 

sinned

Registered Visitor
Thank to all.

In fact, we care only the accuracy of the timer. I told the calibration dept guy that if they can directly calibrate the accuracy of the build-in machine timer, then the whole thing of using stopwatch to check can be eliminated. Now our MSA expert ask us to do GR&R for everything on the control plan, including the stopwatch and tachometer. Or, otherwise, remove the control from the control plan...

What can we do? We really done it...
 

Marc

Fully vaccinated are you?
Leader
It shouldn't be hard to revise the FMEA and from that revise the control plan. But, keep a history of revisions and rational for doing so. If you had meeting(s) to discuss the changes, keep meeting minutes to support your reasons for the changes.

Look at this as continuous improvement and cost reduction.
 
Top Bottom