The scheduling for parallel machines with periodic maintenance and setup activities

Abstract

This paper tackled a parallel scheduling problem for identical machines with periodic maintenance and sequence-independent setup times under a hybrid make-to-order (MTO) and make-to-stock (MTS) environment. Such a production environment is apparent in many capital-intensive and highly competitive high-tech industries; for example, the thin-film-transistor liquid-crystal-display (TFT LCD) industry. To fully exploit expensive machines, maximum throughput is the objective with the constraints of meeting the promised customer orders in each planning period. In this paper, the time interval of maintenance period is a constant. Hence, the planning period is set equal to corresponding maintenance period in order to reduce the problem complexity. Under such environment and Lime bucket setting, an integer programming (IP) model is developed to find the optimal production quantity and production sequence for each machine for throughput maximization. Finally, a practical example is given to demonstrate the applicability of the proposed IP model to cell assembly of a LCD factory.