ELSEVIER European Journal of Operational Research 87 (1995) 564-573 EUROPEAN JOURNAL OF OPERATIONAL RESEARCH Aggregate planning and scheduling in the food industry: A case study* R. Tadei *, M. Trubian, J.L. Avendafio, E Della Croce, G. Menga D.A.L, Politecnico di Torino, C. Duca degli Abruzzi 24, 10129 Torino, Italy Received December 1994; revised May 1995 Abstract In this work we introduce a production scheduling problem encountered in COMPAL S.A., a factory located in Lisbon, Portugal, which produces perishable goods for the food market. The paper shows how to derive a scheduling model from the factory specifications and presents a two-step heuristic procedure for its solution. This research constitutes a good example of a practical OR application involving three different European countries. Keywords: Aggregate planning; Scheduling; Modeling; Heuristics; Local search 1. Introduction In this paper we deal with a practical OR application developed in the BRITE/EURAM project #4140 of the European Community entitled 'ScheduleZ'. This project involves firms, software houses and universi- ties of three different countries: Great Britain, Portugal and Italy. The goal of ScheduleZ is to build up a soft- ware package for the configuration of highly efficient dynamic planning and scheduling systems for manu- facturers of perishable and fast turnover products. Previous works on food and perishable goods pro- duction scheduling are based on heuristic approaches, which seem to be the only way to tackle such prob- lems. An example of a heuristic procedure for a pro- duction planning and scheduling problem with sea- sonal demand is [1]. Other examples of heuristic * This work has been partially supported by the European Com- munity under the contract BREU-CT92-0567. * Corresponding author. E-mail:tadei@polito.it methods for solving problems derived from case stud- ies in the food industry are [ 3,9], where an application of aggregate planning and scheduling is proposed. An earlier version of the scheduling system here proposed can be found in [7]. The paper is organized as follows. In Section 2 the production scheduling system is described. In Sec- tion 3 the scheduling model is presented and in Sec- tion 4 a two-step solution method is developed in de- tail. In Section 5 some computational results are given, which show a mean error of 1.3% from the lower bound. Section 6 concludes the paper with some final remarks. 2. The system Let us concentrate on the part of the overall EC project concerning the production scheduling of COMPAL S.A., a factory located in Lisbon, Portu- gal, which produces alimentary preserves. Its plant 0377-2217/95/$09.50 (~ 1995 Elsevier Science B.V. All rights reserved SSDI 0377-2217 (95)00230-8