Article ID: | iaor20002695 |
Country: | United Kingdom |
Volume: | 38 |
Issue: | 1 |
Start Page Number: | 51 |
End Page Number: | 67 |
Publication Date: | Jan 2000 |
Journal: | International Journal of Production Research |
Authors: | Vercellis Carlo, Dumoulin Aline |
In this paper, we propose a modelling approach for the medium term planning of manufacturing systems characterized by coexisting large volume and small volume products, in which changeovers play a critical role in achieving maximum efficiency. Although the model is based upon the large time bucket paradigm, it is capable of representing start-ups by sequencing the lots of items produced in long sequences. Specifically, we consider a capacitated lot-sizing problem with parallel machines, in which the products have a three-level hierarchical structure; end items are aggregated into families, which in turn are aggregated into types. Minor set-ups and major changeovers take place when switching between families within a type or between types, respectively. The resulting mathematical programming problem is decomposed via Lagrangean relaxation, leading to sub-problems that can be solved in polynomial time. The whole approach has been validated by applying it to large size case studies drawn from the textile industry.