An application of cyclical master production scheduling in a multi-stage, multi-product environment

Abstract

This paper presents an integrated approach to solve a multi-item lot-sizing and scheduling problem in a two-stage flow shop environment. The problem tackled stems from a real world process and the data used are the actual process information. In this production system, all items are produced in two stages. The first stage is process-oriented and produces a limited number of intermediate products. The second stage is flow shop oriented and splits up the intermediate products into a very large number of end products. The objective is to develop an integrated repetitive cyclic master production plan, minimising the total set-up and inventory holding costs of the work-in-process and end products. The problem corresponds with solving the capacitated lot sizing problem in a two-stage, multi-product environment under the additional constraint of repetitive cyclic production schedules. The model will use a level by level approach. A heuristic approach will first establish a common cycle length and production frequencies. Secondly a mixed integer linear program will define the production sequences ensuring a smooth load profile. The proposed solution approach is tested out as the main planning concept within the MPS department of a company producing photographic materials (e.g. X-ray film, graphical film). Agfa, the involved company, has a number one or two selling position in the mentioned product groups. This paper will describe the solution approach, the mathematical model and operational results after one year of practical usage.

Keywords:

• Production planning
• Cyclical scheduling
• Economic lot scheduling problem
• Decomposition approximation approach

Acknowledgments

Frank van den Broecke is a civil engineer, heading the planning department of Agfa's main production plant, located near Antwerp, Belgium. Since 1999 he has combined his operational job with a research position at Ghent University, in the Department of Industrial Management. His research interests are in the fields of production and distribution planning.

Rik van Landeghem is an electro-mechanical engineer, Master in Industrial Management, PhD in Operations Research. He worked from 1983 to 1989 in industry as a manufacturing consultant and in industrial informatics. He joined the BMT group in 1989 where he became successively EDP manager, plant manager of the sheet metal division and finally MIS director. From 1993 onwards he has been a full time professor at Ghent University, as Head of the Department of Industrial Management. He is member of the Institute of Industrial Engineering (IIE), The Council of Logistics Management (CLM) and Euroma. He is a fellow of the European Academy of Industrial Management (AIM). Professor Van Landeghem is an expert in logistics and logistic software systems and their application in industry.

El-Houssaine Aghezzaf holds a PhD in applied mathematics. Over the period 1991–2000, Professor Aghezzaf took positions as assistant, assistant professor and then associate professor at universities as UCL, FUCaM and Al-Akhwayn University. Over the period 1996–2000, he was the graduate program co-ordinator at the School of Business Administration of Al-Akhawayn University. In October 2000 Professor Aghezzaf became a faculty member of the Faculty of Engineering at the University of Ghent, where he is an associate professor in the Department of Industrial Management. His research fields include the design and management of logistic and supply networks, operations research and management science.