Economic aspects in the inspection of multiple geometric tolerances

Recent years have seen an increase in the adoption of geometric tolerances. Often it is possible to find several geometric tolerances defined on a single part. However, this poses inspection issues: the values of the geometric errors may be interrelated; therefore, the presence of multiple tolerances should be considered in inspection design. In this work, a methodology is proposed for planning optimal CMM sampling strategies for multiple tolerances based on the minimization of inspection costs. A model for inspection costs is proposed, which takes into account the influence of the inspection strategy on the measurement and inspection errors costs. The inspection strategy minimizing inspection cost can then be defined. The approach can be adopted both to optimize generic, uniform, sampling strategies, and to generate manufacturing specific strategies, which consider the manufacturing signature. A case study which illustrates the methodology is presented.