An MILP model for planning of batch plants operating in a campaign-mode

Abstract

A mixed integer linear programming (MILP) for the detailed production planning of multiproduct batch plants is presented in this work. New timing decisions are incorporated to the model taking into account that an operation mode based in campaigns is adopted. This operation mode assures a more efficient production management adjusted to the specific context conditions of the considered time horizon. In addition, special considerations as sequence-dependent changeover times and different unit sizes for parallel units in each stage are taken into account. The problem consists of determining the amount of each product to be produced, stored and sold over the given time horizon, the composition of the production campaign (number of batches and their sizes), the assignment, sequencing and timing of batches, and the number of repetitions of the campaign, for a given plant with known product recipes. The objective is to maximize the net profit fulfilling the minimum and maximum product demands. The proposed model provides a useful tool for solving the optimal campaign planning of installed facilities in reasonable computation time, taking different decisions about the operations management.