Assessment on tolerance representation and tolerance analysis in assemblies

Due to the difficulty of modeling the manufacturing deviations reliably, th e existing geometric models, to date, have only considered the exact descri ption of parts and assemblies. Yet, the tolerance representation and propag ation issues in assemblies are crucial to answer parallel design of product and process queries. Many formal and informal methods have been developed. However, most proved special cases of the ANSI Y14.5M-82 specification sta ndard. Also, the descriptions provided in actual solid and feature based de sign modelers are inadequate to ascertain a clear taxonomy of tolerance spe cifications, neither do they help address the assembly tolerance analysis a nd/or synthesis issues. The paper purposes to discuss the tolerance representation schemes as well as their underlying philosophies. Then, because tolerance analysis and tole rance synthesis in assemblies are required, among other tasks, to assign fu nctional tolerances, measure the manufacturability and the interchangeabili ty of parts in assemblies, ease tolerance inspection and evaluate costs of alternative assembly sequences, we shall assess deterministic and statistic al methods.