Reducing Labor Costs in an LTL Crossdocking Terminal

Abstract

Handling freight in a crossdocking terminal is labor intensive and therefore costly because workers must unload, sort, and transfer a wide variety of freight from incoming to outgoing trailers. The e ciency of workers depends in large part on how trailers are assigned to doors around the dock; that is, on its layout. A good layout reduces travel distances without creating congestion, but until now no tools have been available to construct such layouts. We describe models of travel cost and three types of congestion typically experienced in crossdocking terminals, and we use them to construct layouts that minimize the labor cost of transferring freight. We report on the use of our models in the less-than-truckload trucking industry, including an implementation at a terminal in Stockton, California that improved productivity by more than 11%.

An Approximate Cost-Integrated Modelling Approach to Cross Dock Design

“…In addition to internal travel distances, Bartholdi & Gue (2000) introduced the congestion cost due to different types of traffic conflicts. Although of interest, most of the current published research on the subject takes into account just the internal travelling distance, taking this element as a proxy variable used to estimate the total cost of transferring freight from the strip doors to the shipping docks.…”

“…The average distance d is assumed to be an approximation of the total internal travel cost across the dock, and therefore a proxy estimate of the variable labour cost to move freight through the facility (Bartholdi & Gue, 2000. The optimization problem (4) is a combinatorial problem with the following formulation: (a) from the total of m 1 + m 2 available dock doors, select m 1 doors to be used as strip doors according to some appropriate criterion, and m 2 doors to be stack doors; (b) assign each one of the m 2 stack doors to a specific destination.…”

“…This, of course, will depend on specific arrangements with suppliers. Another research possibility is to introduce the congestion effects in terminal performance and costs, due to different types of internal traffic conflicts, as reported by Bartholdi & Gue (2000).…”

Designing a location-routing model for cross docking in green supply chain

“…This is evident in increased volume of commercial transactions, high income and money making that an efficient and successful supply chain brings forth. This has caused such firms to surpass their rivals in today's highly competitive markets (Donaldson et al, 1998;Bartholdi III & Gue, 2000Chen et al, 2006;Galbreth et al, 2008;Gue & Kang, 2001;Gümüş & Bookbinder, 2004;Vis & Roodbergen, 2008, Waller et al, 2006. Current technology is gaining momentum towards specialization and globalization.…”

Vis-à-vis vs. mixed dock door assignment: A comparison of different cross dock layouts

“…• Destination assignment, which covers the mid-term assignment of dock doors to inbound and outbound destinations, is treated by Chang (1990, 1992), Gue (1999), Bartholdi and Gue (2000), Bermudez and Cole (2001), Oh et al (2006) as well as Bozer and Carlo (2008). In real-world operations such an assignment is xed over a longer planning horizon, e.g., a month, and all trucks serving the respective destination are processed at the same door.…”