P • A • R • T • 6
Measurement Systems Analysis
Gregory A. Hetland, Ph.D.
Hutchinson Technology Inc.
Dr. Hetland is the manager of corporate standards and measurement sciences at Hutchinson Technol-
ogy Inc. With more than 25 years of industrial experience, he is actively involved with national, interna-
tional, and industrial standards research and development efforts in the areas of global tolerancing of
mechanical parts and supporting metrology. Dr. Hetland’s research has focused on “tolerancing opti-
mization strategies and methods analysis in a sub-micrometer regime.”
Measurement methods analysis is a highly critical step in the overall concurrent engineering process.
Today’s technology advancements are at a stage where measurement science is being pushed to the limit
of technological capabilities. The past has allowed capabilities of measurement equipment to be accept-
able if the Six Sigma capability was > 1 µm (0.001 mm). Today, submicrometer capability is much more the
norm for high technology manufacturing firms, with the percentage of features in this tolerancing regime
getting larger and larger.
The primary objective of this chapter is to generate a capability matrix that reflects “Six Sigma capa-
bility” for all 14 geometric controls, as well as individual feature controls using an ultra-precision class
coordinate measuring machine (CMM). In this particular case, a Brown & Sharpe/Leitz PMM 654 En-
hanced Accuracy CMM was used for all testing to generate this matrix.
Analysis included variables that impact optimum measurement strategies in a submicrometer regime
such as feature-based sampling strategies, calculations for determining capability of geometrically de-
fined features, the thermal expansion of parts and scales, CMM performance, and submicrometer capabili-
ties in contact-measurement applications.
20-2 Chapter Twenty
The methodologies for approaching the characterization of CMMs as a whole is ext