Tolerance analysis in setup planning for rotational parts

Tolerance analysis is crucial in process planning for precision manufacturing; however, very few computer-aided process planning (CAPP) systems are capable of performing tolerance analysis. At most, tolerance analysis is used to check the dimensional tolerance stackups rather than generating optimal setup/process plans. Recently, some researchers have begun to recognize the importance of tolerance analysis in generating appropriate setup/process plans. Although some rules of thumb have been developed for automated setup planning, no systematic approach is available in the literature. In this paper, a graph-theoretical approach is proposed to generate setup plans based on tolerance analysis. The design specification of a part is represented as a graph. The problem of identifying the optimal setup plan is transformed into a graph search problem. A setup planning algorithm for rotational parts is then developed and implemented. The algorithm is evaluated using Monte Carlo simulation and found to be effective. The graph-theoretical approach is very useful for solving the setup planning problem. The advantage of the approach is that it is a mathematical approach and can be easily evaluated, modified, and computerized.