A heuristic approach for the capacitated lot sizing problem with alternatives of renewable energy sources

In this paper, a new single item lot sizing problem, including different energy sources is addressed. The objective is to build a mathematical model that determines the optimal production planning and energy contracting that minimizes production and energy costs in terms of production system constraints and energy supplier contract conditions. Since the problem is NP-Hard, a Fix-and-Relax heuristic is introduced to solve the problem. Two types energy sources (traditional and renewable) are considered. The choice of energy contract value is also considered in terms of capacity. Computational results are exposed to evaluate the model on hand.