A new algorithm for discrete tolerance optimization

A new algorithm has been developed which deals with the problem of least cost tolerance allocation with process selection. This algorithm uses the combinatorial nature of orthogonal arrays and experimental optimization techniques to allocate the magnitude of tolerance to each design dimension and select the corresponding manufacturing process. Interaction graphs are used to assign the dimensional tolerances to various orthogonal array structures. The proposed algorithm is capable of dealing with continuous and discrete cost functions as well as linear, nonlinear and multi-loop assembly functional requirements. Several examples are used to illustrate the effectiveness of the developed technique. Results indicate the superiority of the developed algorithm with those obtained using discrete, combinatorial, combined discrete and continuous and sequential quadratic programming