The general lot sizing and scheduling problem with sequence dependent changeovers

Thesis Type: Postgraduate

Institution Of The Thesis: Middle East Technical University, Faculty of Engineering, Department of Industrial Engineering, Turkey

Approval Date: 2005

Thesis Language: English

Student: Ayşe Koçlar

Supervisor: HALDUN SÜRAL


In this study, we consider the General Lot Sizing and Scheduling Problem in single level capacitated environments with sequence dependent item changeovers. Process industries may be regarded as suitable application areas of the problem. The focus on capacity utilization and intensively time consuming changeovers necessitate the integration of lot sizing and sequencing decisions in the production plan. We present a mathematical model which captures the essence of cases in the most generic and realistic setting of the problem. We discuss the impact and validity of some of the assumptions commonly encountered in the related literature. We also represent the problem using an alternative formulation and attempt to enhance the formulations with the use of some additional inequalities. Finally, we develop a heuristic by restricting the number of possible changeovers. Computational results are discussed.