Production Scheduling with Energy Efficiency Constraints

Abstract

This research is motivated by a real world production scheduling problem in a continuous manufacturing system involving multiple objectives, multiple products and multiple processing lines with various inventory, production and energy efficiency constraints. Because of the conflicting objectives, an optimization approach is considered as not feasible by the plant management. Given a customer demand forecast, three practical heuristic algorithms are developed to generate daily production schedules for three conflicting objectives: minimize shipment delays, minimize average inventory levels, and minimize product switch-over to avoid energy waste. Since each heuristic is designed to give priority to one of the three conflicting objectives, none of them is absolutely superior to the other algorithms in all aspects. However, the management can assign weights to each of the three objectives to identify the schedule that minimizes the total cost index.