Early cost estimation for tolerance verification

This paper presents a methodology for estimating the verification cost of geometric tolerances at the design stage, which is useful for optimizing the tolerance specifications of mechanical products. The tolerance verification cost may be seen as the sum of the measurement and uncertainty costs. The measurement cost depends on the adopted device and on the measurement time. The uncertainty cost is related to type A (declaring a conforming part non-conforming) and type B (declaring a non-conforming part conforming) errors: these errors are strongly influenced by the measurement procedure, which depends on the measurement device and determines the measurement time. The methodology is illustrated and validated using simulation and industrial case studies. (C) 2011 CIRP.