SKEDSOFT

Gauge R&R: Gauge R&R (Crossed) with Xbar & R Analysis (cont.):

Example SupposeR&R = 32.0 and Part = 89.0. Calculate and interpret the %R&R.

Answer: %R&R = (100% × R&R) ÷ sqrt[R&R2 Part2] = 33.8%. Using standard conventions, the gauge is not capable even with lenient standards.  However, the measurement system might be acceptable if the parts in the study are much more similar than parts of future interest. Specifically, if the person only needs to tell the difference between parts with true differences greater than 6.0 × 32.0 = 192 units, the measurement system being studied is likely acceptable.

Step 2 that can make the calculations in Step 3 easier to interpret and to perform correctly.

 It is probably desirable, however, to create a table as indicated in Step 1 first before reorganizing. This follows because otherwise one might be tempted (1) to perform the tests in a nonrandom order, or (2) to change the results for the later trials based on past trials.

Example Gauge R&R (Crossed) Arc Welding

A weld engineer is analyzing the ability of two computer software programs to measure consistently the undercut weld cross sections. She performs Steps 1 and 2 of the gauge R&R method and generates the data in Table.