Minimizing the operating cost of block retrieval operations in stacking facilities

Abstract

This paper addresses the Blocks Relocation Problem with Operating Costs, whose main objective is to retrieve a set of blocks from a stacking facility while minimizing the operating cost. An integer programming model and a deterministic algorithm are developed to solve the problem from an exact standpoint. Both approaches are able to solve the problem optimally only for small size problem scenarios, requiring large amount of computational time and memory in medium and large size problem instances. On the other hand, a heuristic algorithm based on A∗ is also proposed with the goal of reducing considerably the computational resources, allowing to solve large problem instances. The computational results disclose this algorithm generates high-quality solutions in reasonable computational times.