Building a Multi-Objective Model for Multi-Product Multi-Period Production Planning with Controllable Processing Times: A Real Case Problem

Model building is a fragile and complex process especially in the context of real cases. each real case problem has its own characteristics with new concepts and conditions. a correct model should have some essential characteristics such as: being compatible with real conditions, being of sufficient accuracy, being logically traceable and etc. this paper discusses how to build an efficient model for a real case production planning problem. this process is reinforced by providing the proofs confirming the special characteristics of the final model such as proving its np-completeness. also, the extremes of both objective functions – production smoothing versus cost minimizing – are calculated analytically. finally, the case study and its solution methods are discussed briefly.