Lot scheduling problems of multiple items in the shop with both receiving and delivery just in time

Abstract. This paper deals with lot scheduling problems of multiple items processed in the shop with either a single machine or heterogeneous machines, under the condition that parts to be processed must arrive at the production line at the right times in the right quantities, and that completed parts must be delivered at their due date. Each of the problems is divided into subproblems of lot sizing and scheduling the resulting lots. Solution procedures solving the subproblems are separately optimal. However, since one of the subproblems is not independent of the other, the proposed algorithms adopting these procedures are to be considered heuristic. An iterative procedure is provided to improve solutions. The performance measure used is that of minimizing the total actual flow time considering both receiving just in time and delivery just in time. Numerical examples are presented to show the implementation of the algorithms.