Note—Sequencing JIT Mixed-Model Assembly Lines

We provide a new formulation and solution procedure to sequence a mixed model just-in-time (JIT) assembly system. Mixed model JIT assembly systems are a fundamental part of the well-known “Toyota Production System.” The underlying idea in sequencing these systems is to maintain a constant usage rate of all parts on the line. We give a polynomial algorithm to determine the optimal sequence for an objective function that is mathematically different, but intuitively similar to the objective functions of previous researchers. Furthermore, a computational study indicates that the new algorithm is robust in that its sequences are as good as those generated by other algorithms when evaluated with respect to traditional objectives, but are found 200 times faster.