Design optimization modeling for customer-driven concurrent tolerance allocation

The majority of previous studies on tolerance allocation have viewed the issue as a design methodology to determine optimal component tolerances on behalf of a manufacturer, while meeting given assembly tolerance requirements. Although a considerable amount of research has been done on this issue, a couple of important questions still remain unanswered. First, how can a design engineer quantitatively incorporate a customer's perception on a product quality into a tolerance allocation scheme at the early design stage? Second, how can component tolerances and assembly tolerance be optimized in a simultaneous way? To answer these questions, this paper presents the so-called customer-driven concurrent tolerance allocation which is facilitated by the notion of truncated distribution and the use of mathematical programming techniques, while adopting the major principles of Taguchi philosophy. The procedures are demonstrated in a numerical example. The work presented in the paper is an effort to gain insights, which can be useful in practice when setting up guidelines for an overall tolerance allocation.