Scheduling of multistage fast-moving consumer goods plants

Fast-moving consumer goods plants are required to be highly flexible due to their multiproduct nature and frequent portfolio changes with seasons or consumer preferences. The multipurpose nature of equipment units usually results in changeover activities which can increase the production scheduling model's size significantly. The objective of this paper is to present two approaches to decrease the number of changeover activities. The first approach aims to reduce unit flexibility by reducing the allowable task to unit allocations. The second approach emphasises sequencing operations on units. By limiting the set of possible task sequences in the scheduling problem, the number of allowable activities (especially changeovers) is decreased and the optimisation procedure has a smaller search space. The results of these approaches, tested against realistically sized instances indicate their effectiveness in reducing the model size and the solution time, enabling the solution of industrial examples which previously could not be solved.