Optimal sequencing of production and inspection operations

In this paper the authors extended the treatment of the inspection location problem to allow for the case when the order of production operations has not been determined yet, and they wish to find the combined sequence of production and inspection operations that minimizes the expected total cost per unit that exits the production system. In addition, the model formulation allows for the parameters of the inspection operations to vary according to the preceding operations in the sequence. The problem is solved with a branch and bound procedure which includes a heuristic for finding a reasonably good solution to serve as the initial upper bound. The authors also show that under certain assumptions regarding the characteristics of the operations involved it is possible to reduce significantly the search effort by applying a relationship of dominance between partial sequences.