The economic lot scheduling problem – survey and linear programming-based method

In order to solve the ELSP (Economic Lot Scheduling Problem) you can find three approaches with different restrictive assumptions in the literature: Common-Cycle-Approach; Basic-Period-Approach; Varying-Lot-Sizes-Approach. In this paper the ELSP is presented as a linear mixed-binary model. With the help of this model the three approaches, which will be described, can be combined with or without a 2^x-policy and can be solved for little instances. This is based on an approximation of the inventory holding costs with a mistake of 0.3% at the most and of an optional scheduling in order to reduce the number of variables and constraints. For bigger instances there will be two steps that come before the solution of the basic model. In these steps frequencies of production and scheduling are coordinated with each other. The result is that only the continuous lot sizes and the adaptation of the cycle time has to be worked out for this input.