Besides being a widely studied area in operations research and in industrial and management science, production planning is considered one of the most fundamental elements in manufacturing systems. Due to the nature of the features involved in production planning problems, Mixed Integer Programming (MIP) is commonly used for optimization in this area. Also, the flexibility of MIP allows addressing specific problem characteristics and assumptions. This thesis tackles a multi-item multi-level capacitated production planning problem by MIP with a particular feature found in certain industries: raw material shelf-life. Manufacturing systems such as food, chemicals, composite materials and related industries, utilize components that are subject to limited shelf-life and must be disposed if they reach the end of it. Two MIP model formulations are proposed here: one without raw material shelf-life requirements as a basis of comparison, and one integrating raw material shelf-life. The models are flexible enough to be applied and validated for multiple problem instances with different variations and for an Automotive Industry case study. IBM® ILOG® CPLEX® Optimization Studio is used to achieve optimality. Results are analyzed and discussed in depth and future research topics are proposed.
Keywords:
production planning; mixed integer linear programming; shelf life; composites manufacturing