An Operational Tolerance Allocation Method with ProbabilisticProcess Capability

摘要

Tolerance allocation is carried out usually in two stages: design and process planning. Design engineers allocaterntolerances to individual components to satisfy the assembly tolerance requirements. Process planners distribute therncomponent’s design-specified tolerances among the various operations required for the production of thatrncomponent. Several tolerance allocation methods have been proposed over the years. The majority of the tolerancernallocation models are optimization based, many of which are based on the cost-tolerance functions. These modelsrnconsider the process capability as a single value representing the worst-case performance of the process. Processrncapability is more accurately represented as a probabilistic entity. This paper presents an operational tolerancernallocation model in which the process capability is formulated as a stochastic distribution. The results indicate thernsuperiority of the proposed model over the traditional tolerance allocation methods.