Track: Production Planning and Management

Abstract

Production systems generally struggle with defective products resulting from human error, machine break-down, or an imperfect production system. Reworking is one of the strategies to deal with this issue, and rework planning involves the production planning and scheduling of defective items and master production planning. The importance of rework planning becomes more important when the products are perishable with a limited lifecycle. This research presents a linear bi-objective mathematical model to determine the production lot-sizing and scheduling and rework scheduling in a parallel machine system for perishable products. The optimization model aims to minimize the cost and the makespan of the production and rework processes simultaneously. We test the model results on a small size problem with three distributional scenarios solved using optimization algorithms and address the large size problem's complexity using the BAT metaheuristic algorithm. The results indicate a 5% reduction in reworking process time, and metaheuristic finds solutions on the average less than sixty seconds. Numerical experiments and sensitivity of the results to the model varying parameters are analyzed on a sample case study with varying sizes.