Jack E. West’s picture

By Jack E. West

Perhaps no concepts have been more abused than those related to controlling measurements. For decades it was common in many industries to calibrate measuring and test equipment to ensure it met its own specifications for accuracy and precision. Complex and expensive systems were developed to do the calibrations as scheduled. There was little emphasis on controlling the relationship between the requirements being measured and the precision, accuracy, and stability of the overall measurement system. I’ve seen many situations where measuring devices had tolerances that were looser than the tolerances of the characteristic being measured, and caused the entire control loops to behave erratically--and the managers all wondered why.

By the time ISO 9001 was first issued in 1987, this had begun to change. Some industries had begun to emphasize what should be measured so that appropriate measurement equipment was selected. Still, even today it’s not uncommon to see the wrong equipment being used for a measurement. The most important focus in this area is to establish controls to ensure that measurement capability exists. In other words, the measurement system must be accurate and precise enough to ensure that measurements meet measurement requirements.

Denise Robitaille’s picture

By Denise Robitaille

On several occasions while conducting a third-party surveillance audit, I’ve gotten the following query--or a variation thereof: “One of our customers called us last week and wants to come in to do an audit in three weeks. Why can’t they just accept the results of the audit that you’re doing? After all, they’re auditing us to the same requirements. Isn’t registration to ISO 9001 supposed to stop these multiple customer audits?”

It does seem to be a dreadful waste of time. When any auditor comes in, there’s the need to have staff available for interviews. There’s at least one individual--usually the quality manager--who loses one or more days escorting the auditor throughout the facility. Schedules are disrupted; important tasks get sidelined.