A hybrid electromagnetism-like algorithm for integration of process planning and capacitated lot-sizing problem

The capacitated lot-sizing problem (CLSP) is extensively discussed in the operation management literature. The CLSP concerns balancing set-up costs against inventory costs under a common capacity constraint, and considers a limited time horizon such that total costs can beminimized. In this regard, the integration of process and production planning is essential to improve system performance. This paper proposes a model for the integration of process planning and production planning for turning parts that can be implemented in CLSP. The developed model simultaneously considers the technology-related constraints and shop floor constraints determined by the available time. In this approach, two new variables are defined for CLSP: part machining time and cost. This model takes the maximum depth of cut and feed rate for each feature with regard to technology constraints, and the spindle speed is selected in CLSP. Since the proposed optimization model is included in the class of NP-hard problems, a hybridization of two meta-heuristic algorithms (an electromagnetism-like algorithm and a simulated annealing algorithm) is used to solve the problem in acceptable time. Finally, the algorithm proposed in this paper is applied on a case study, and the results are discussed.