Aggregate production planning models using switching control strategy

Abstract

The production switching heuristic (PSH) is recognized as an effective solution method for the aggregate production planning problem in industries where production is limited to discrete levels. The purpose of this thesis is to develop and evaluate improved versions of the PSH by incorporating some practical aspects into the switching mechanism of the PSH. Also, a switching heuristic is developed for an aggregate production planning in the multi-products batch manufacturing system. In the first part of the thesis, two improved versions of the PSH are proposed. The first heuristic uses an improved switching mechanism which can be shown to dominate the PSH. To reflect the practical managerial view on inventory related issues, the concept of the target inventory ratio is integrated into the second heuristic. On the basis of some properties of the heuristics, an efficient search procedure is developed for switching control parameters of the heuristics. The effectiveness of the proposed heuristics is investigated with several well-known problems including the paint factory problem. The results are compared with those of the linear decision rule and the linear program model as well as the PSH. Also, a mixed integer program model is utilized to evaluate the heuristics exactly when the cost function is linear. The second part of the thesis deals with the aggregate production planning models which use the concept of hysteretic control in their decision rule. Two flexible switching heuristics are developed on the basis of the models proposed in the first part of the thesis. In these heuristics, a production rate for the next period is selected considering the production rate in present state as well as the net production requirement. A heuristic search procedure is developed for the determination of the switching control parameters. Through example problems, the effectiveness of the heuristics is demonstrated. A mixed integer program model is developed to evaluate the ...