On the feasibility of sequence-dependent economic lot scheduling problem

Abstract

In this paper, we develop a formulation for the economic lot scheduling problem (ELSP) wherein products with sequence-dependent setups are to be scheduled on a single facility to minimise the average sum of inventory holding and setup costs. We show that our formulation, based on the time varying lot size approach, always provides feasible schedules for any given sequence and is independent of the setups being sequence-independent or sequence-dependent. We compare our schedule with the schedule proposed by Dobson (1992) and reveal the infeasibility associated with Dobson's formulation. A numerical example evaluating schedules with both cases of setups: sequence-independent and sequence-dependent, demonstrates our assertion.

Keywords:

• economic lot scheduling problem
• time varying lot sizes
• sequence-dependent setups