We perform a destructive test using a digital force gage to measure the strength of a container joint. The problem is this: the process is out of control to the point that sequential parts have a lot of variation. With a typical Gage R&R, one would take parts from one batch and assume that they are nearly identical. In our case, we know that the range of measurements is too large to assume this. In fact, I did a Gage R&R and the result was almost 200%! I made a breakaway fixture with latches that seems very repeatable (std. dev. of a little more than a pound with a mean of approximately 40 pounds). However, if I use multiple operators to take measurements using this breakaway fixture, and plug this into the traditional formula that assumes I am retesting the same part, I get a very large (over 30%) unacceptable R&R result. I believe on or more of my assumptions may be incorrect. If I can get a reasonable number, we can start our effort to improve the manufacturing process itself. I have no reason to believe that the force gauge or method is not repeatable. I've used two different gauges with similar results. Any ideas?