Function-oriented Measurements – The Path from Macro to Micro and Nano Range

Abstract In order to understand the background of today's geometrical product specification and verification, a brief historical review on the development of our present rules for dimensioning and tolerancing and its importance for manufacturing metrology are given. It is pointed out that nowadays the designer is responsible for defining the functional related geometrical limits, but it is the inspector, who decides about the functional ability of a workpiece by his choice of measuring methods and equipment. Exemplarily presented function-oriented measurement methods seem to be very dif-ferent for workpieces in macro range and for micro- and nanostructures. But most of these function-oriented methods have in common that they are based on a model of the function, which represents the causal interrelation between surface geometry and surface functionality. So a general approach to assess the functional ability of a workpiece is based on a parameterized mathematical-physical model of the function, which is used like a kind of “virtual functional gauge” by simulating the functional behaviour of even complex cause- effect relationships.