A Lagrangean heuristic algorithm for disassembly scheduling with capacity constraints

Abstract

This paper considers the problem of determining the disassembly schedule (quantity and timing) of products in order to satisfy the demand of their parts or components over a finite planning horizon. The objective is to minimize the sum of set-up, disassembly operation, and inventory holding costs. As an extension of the uncapacitated versions of the problem, we consider the resource capacity restrictions over the planning horizon. An integer program is suggested to describe the problem mathematically, and to solve the problem, a heuristic is developed using a Lagrangean relaxation technique together with a method to find a good feasible solution while considering the trade-offs among different costs. The effectiveness of the algorithm is tested on a number of randomly generated problems and the test results show that the heuristic suggested in this paper can give near optimal solutions within a short amount of computation time.

Keywords:

• environmental studies
• production and scheduling
• heuristics

Acknowledgements

The financial supports from the Swiss National Science Foundation (SNF) under contract number 2000-066640 and the Korea Research Foundation grant (KRF-2004-03-D00468) are gratefully acknowledged.