1 Introduction
As companies try to cut down shipping costs and provide a better service to their customers, the attention of
supply chain managers turned to cross-docking. Cross-docking is described as the flow of material directly
from receiving to shipping, where the goal is minimal handling and virtually no storage [1]. This new
method of distribution management has gained a great reputation in helping companies cut their overall
shipping costs and achieving better service levels.
As cross-dock operations were first pioneered in the US trucking industry in the 1930s, they became
exceptionally popular after the great success of Wal-Mart utilizing cross-docking in the retail sector in the
1980’s [2].
Cross-docking is the practice of routing trucks from origin to destination either directly or indirectly
through cross-dock facilities (CDF). At the CDFs, trucks unload their shipments and become available for
other requests, and the shipments are consolidated and loaded onto other outgoing trucks in order to reach
their final destinations. The customer is known in advance before the product arrives to the CDF so that the
storage is minimized or eventually eliminated [3].
In this study, we propose a discrete event simulation model of cross-docking operations where orders are
placed randomly through three different warehouses. Trucks transporting different orders are routed from a
warehouse to a destination directly or indirectly through CDFs. Orders to be shipped are subject to delivery
time constraints. The service level, truck utilization, the number of CDFs, and the number of trucks
scheduled are taken into account.
The paper is organized as follows: In section 2, a literature review about cross-docking simulation
models is presented. In section 3, we present a brief description of our proposed simulation model with our
assumptions. Section 4 describes the technical details of our simulation model. In section 5, we present our