Assessing the Health of a Measurement System

R&R studies ensure your measurement system can measure process variation

Published: Thursday, November 1, 2018 - 11:03

Measurement devices in manufacturing facilities are as ubiquitous as Skittles in trick-or-treat bags. Some companies have thousands of devices in their inventories and depend on them to provide accurate information. This is why timely calibration of all measurement devices is critical to manufacturing efforts.

While process improvement initiatives, including statistical process control (SPC), can get the greatest attention in manufacturing environments, frequently the backbone of a quality improvement effort is the quiet, often unnoticed, measurement devices that represent an organization’s commitment to consistency and accuracy. These silent workers give vital information by providing meaningful measurements and assurance about whether products are ready to ship or not. They deserve to be treated as a top priority.

Yet a critical, and often overlooked, part of the journey toward reducing variation and continuously improving is developing confidence in the system used to measure the process, parts, or products. Most of the improvement efforts in organizations are spent on reducing variation among products. Little, if any, attention is paid to the variation introduced into the overall picture due to the measurement system.

While other sources of measurement variation exist, the two primary sources are equipment variation (repeatability) and appraiser variation (reproducibility). Conducting R&R studies can shed light on issues that may not be apparent with calibrations alone. Reducing R&R variation to the lowest amount possible allows better detection of variation in the actual product being produced.

Having calibration and maintenance processes in place, without R&R studies, leaves a serious gap in assessing the health of the measurement system. There is a real danger that the information provided by these well-maintained measurement instruments is of little practical use because the variability in the manufacturing process is being drowned out by excessive variability in the measuring process. 

At first glance, R&R studies may seem overly complex and to the uninitiated can appear to be a daunting challenge. However, with review of the inputs and outputs, the concepts can be easily learned. There are plenty of techniques that can maximize the time and effort to get to meaningful results.

Evaluation of measurement systems should be an important element of any continuous improvement activity. The evaluation, through R&R studies, builds trust in the instruments, operators, and processes. An understanding of measurement system variation helps to provide a full understanding of a process so that its future performance can be better predicted and a more consistent product delivered to the customer.

Join us on Nov. 6, 2018, at 11 a.m. Pacific/2 p.m. Eastern for the webinar, “The Importance of R&R Studies.” Find out how R&R studies can improve your understanding of your measurement systems and advance your quality efforts. Register here.

About The Author

Eric Gasper

Eric Gasper brings a rich background of technical and business analysis, web development, consulting, and team leadership to his role as trainer-consultant for PQ Systems. Experience in laboratory and office environments has given him a unique perspective on a variety of technical problems as well as insight into customers’ unique challenges. Gasper holds a bachelor’s degree in management information systems from the University of Dayton, where he garnered experience with the university’s famed Research Institute prior to entering the work force as a business analyst and development specialist in pharmaceuticals for a major consulting company.