Gage R & R

This past week I spent most of my time putting finishing touches on the program for the system I am working on. The three machines in the system are running fairly well though as they are put through their paces we are always finding small things that need to be adjusted, coded or otherwise changed. We are however able to produce properly assembled parts that have been accurately tested throughout the process.

As part of the verification of the machinery we performed a Gage R & R (Repeatability and Reproducibility) on the leak testers. This is a quality technique that analyzes variations in test results as a possible result of the gage or measurement device used, or operator interpretation and use. It is part of the DMAIC aspect of Six Sigma.

For this process we ran tests on five different parts three times each, logging the results for each part to a spreadsheet. Parts were run in random order. This was then repeated by two more operators to determine whether different people would perform the tests and load the parts in the same manner. This is important since part of the assembly operation is manual. The variations were then analyzed using X Bar R, averages and spread for each operator and part. This not only helps establish R & R for the leak testers themselves but also for the associated tooling and programming. It can help identify where changes in hardware, software or procedures need to be made.

It also helps reinforce for me why I would not want to be a machine operator in a factory. Performing the same operation on the same parts over and over again gets pretty monotonous. I would also not want to be a manufacturing engineer since I am always happy to wave goodbye to a machine as it leaves.


Electrical Engineer and business owner from the Nashville, Tennessee area. I also play music, Chess and Go.