This paper provides a brief presentation of simulated annealing techniques and their application in lot sizing problems. By using a binary matrix to describe lot sizing decisions, it is ready to model this type of production/ inventory system as a combinatorial optimisation problem and solve it within the simulated annealing framework. Experiments are conducted in order to understand how different aspects of the algorithm, especially the annealing schedule, affect the quality of the solution. (C) 2003 Elsevier B.V. All rights reserved.