Approaches for the Order-Picking Problem in Parallel-Aisle Warehouses

DATE: November 6, 2009

TIME: 12:00 PM – 1:00 PM

LOCATION: Executive classroom

FEES: none

EVENT CONTACT:

Anita Race, H. Milton Stewart School of Industrial and Systems Engineering
Contact Anita Race

TITLE: Approaches for the Order-Picking Problem in Parallel-Aisle Warehouses

SPEAKER: Melih Celik

ABSTRACT:

Order-picking operations constitute the costliest activities in a warehouse. The order-picking problem (OPP) aims to determine the route of the picker(s) in such a way that the total order-picking time, hence the order-picking costs are minimized. In this study, a warehouse that consists of parallel pick aisles is assumed, and various versions of the OPP are considered.

The single-picker version of the OPP can be solved to optimality in polynomial time for warehouses without middle aisles. However, no polynomial time algorithm exists for the cases where middle aisles exist. In this study, we briefly discuss the complexity of the problem when middle aisles exist and propose a heuristic procedure, which makes use of the exact algorithm for the OPP with no middle aisles. Computational results on randomly generated problems are given.

Although the single-picker version of the problem has been well studied in the literature, the multiple-picker version has not received much attention in terms of algorithmic approaches. For this case, we propose an evolutionary algorithm that makes use of the well-known cluster-first, route-second and route-first, cluster-second heuristics for the Vehicle Routing Problem. The parameters of the algorithm are determined based on preliminary runs and the algorithm is also tested on randomly generated problems, with different weights given to the cluster-first, route-second and route-first, cluster-second approaches.

This study is part of a master’s thesis work in Middle East Technical University (Turkey) under the advisory of Dr. Haldun Sural.