An Effective Two Stage Evolutionary Algorithm for Integration between Production Scheduling and Production Capacity Planning

In this paper we investigate a production scheduling problem integrated with a planning level decision in a manufacturing supply chain. Generally the decisions in different levels of supply chain are considered independently while the feasibility of operational decisions strictly depends on the accuracy of forecasts made in tactical level. Hence, this paper suggests the integration between a special kind of job shop scheduling problem and a capacity planning issue with makespan criterion. The former problem represents an operational decision making while the latter is related to a tactical decision of supply chain. The capacity of production stages are proposed to be determined based on the amount of resources allocated to them, whereas in traditional scheduling problems the production capacity are fixed parameters. After model development, the problem is decomposed to two subproblems and an effective two stage evolutionary algorithm with a local search is designed to effectively solve the considered problem. In order to investigate the model, some benchmark problems are considered and computational experiments show the reliable performance of suggested approach