Robert H. Nickolaisen, P.E.
Dimensional Engineering Services
Robert H. Nickolaisen is president of Dimensional Engineering Services (Joplin, MO), which provides
customized training and consulting in the field of Geometric Dimensioning and Tolerancing and re-
lated technologies. He also is a professor emeritus of mechanical engineering technology at Pittsburg
State University (Pittsburg, Kansas). Professional memberships include senior membership in the Soci-
ety of Manufacturing Engineers (SME) and the American Society of Mechanical Engineers (ASME). He
is an ASME certified Senior Level Geometric Dimensioning and Tolerancing Professional (Senior GDTP),
a certified manufacturing engineer (CMfgE), and a licensed professional engineer. Current standards
activities include membership on the following national and international standards committees: US
TAG ISO/TC 213 (Dimensional and Geometrical Product Specification and Verification), ASME Y14.5
(Dimensioning and Tolerancing), and ASME Y14.5.2 (Certification of GD&T Professionals).
Traditional Approaches to Dimensioning and Tolerancing
Engineering, as a science and a philosophy, has gone through a series of changes that explain and justify
the need for a new system for managing dimensioning and tolerancing activities. The evolution of a
system to control the dimensional variation of manufactured products closely follows the growth of the
quality control movement.
Men like Sir Ronald Fisher, Frank Yates, and Walter Shewhart were introducing early forms of
modern quality control in the 1920s and 1930s. This was also a period when engineering and manufac-
turing personnel were usually housed in adjacent facilities. This made it possible for the designer and
fabricator to work together on a daily basis to solve problems relating to fit and function.
The importance of assigning and controlling tolerances that would consistently produce interchange-
able parts and a quality product increased in importance during the 1940s