Abstract
Warehousing includes many different regular activities such as receiving, batching, picking, packaging, and shipping goods. Several authors indicate that the picking operation might consume up to 55% of the total operational costs. In this paper, we deal with a subtask arising within the picking task in a warehouse, when the picking policy follows the order batching strategy (i.e., orders are grouped into batches before being collected) and orders are received online. Particularly, once the batches have been compiled it is necessary to determine the moment in the time when the picker starts collecting each batch. The waiting time of the picker before starting to collect the next available batch is usually known as time window. In this paper, we compare the performance of two different time window strategies: Fixed Time Window and Variable Time Window. Since those strategies cannot be tested in isolation, we have considered: two different batching algorithms (First Come First Served and a Greedy algorithm based on weight); one routing algorithm (S-Shape); and a greedy selection algorithm for choosing the next batch to collect based on the weight.
Eduardo García Pardo
Full Professor
One of the founders of the investigation group GRAFO, whose main line of research is the development of algorithms to tackle optimization problems, the topic of the researcher’s Doctoral Thesis and which their most notable publications are framed.
Abraham Duarte
Full Professor
Abraham Duarte is Full Professor in the Computer Science Department at the Rey Juan Carlos University (Madrid, Spain). He has done extensive research in the interface between computer science, artificial intelligence, and operations research to develop solution methods based on Computational Intelligence (metaheuristics) for practical problems in operations-management areas such as logistics and supply chains, telecommunications, decision-making under uncertainty and optimization of simulated systems.