Travel Distance Estimation in Single-block ABC- Storage Strategy Warehouses

Abstract

Order picking has been considered as the most critical operation in warehousing. Four mayor components that greatly affect the efficiency of the operation are the routing method, the storage strategy, the warehouse layout and the batching policy. While the routing in warehouse problem, to some extends, has been investigated thoroughly, the others have not been widely studied. One of the essential problems that need to be solved when dealing with these problems is the problem of estimating the average travel distance of a picking tour.This paper deals with the problem of estimating the average travel distance in picker-to- parts narrow-storage-aisle ABC-storage strategy warehouses. We first propose a formula that enables us to estimate the average travel distance within a storage-aisle. Applying this formula, we then derive formulas for the average travel distance of a pick tour in a typical multiple-aisle warehouse. The routing policy used is the return heuristic, meaning that order pickers only enter storage-aisles containing picks and they enter and leave the storage-aisle from the same end. To test the quality of the formulas we built several simulation models. We found that the differences between results obtained from simulation and analytical models were negligible. The findings provide a concrete foundation for two promising optimization problems: storage zone boundary and layout optimization problem.Key wordOrder pickingstorage strategytravel distance estimation