The current operational paradigm at less-than- truckload (LTL) cross-dock industry (i.e., dedicated strategy) is to assign one material handler (MH) per inbound trailer. As a consequence, each loaded trip performed by a MH to move a load from the assigned inbound door to the loads’ corresponding outbound door is followed by an identical empty trip to return to the inbound door. This paper introduces the monomaniacal strategy as a practical rule-based material handling collaborative strategy for LTLs designed to minimize the total empty travel. In the monomaniacal strategy, after delivering a load to an outbound door, MHs travel counterclockwise to the next available inbound trailer. Several mathematical formulations are presented to compare the proposed strategy to the current operational paradigm in terms of the total material handling distance required to unload all trailers. It is concluded that the proposed monomaniacal strategy outperforms the dedicated strategy without considering that loads have (LIFO) precedence constraints by an average of 17.45% and is within 25.59% of the theoretical optimal solution that requires a centralized decision support system. Other experimental results suggest that the optimal inbound door assignment for the monomaniacal strategy coincided with the optimal inbound door assignment for the dedicated strategy and that the optimal solution for the monomaniacal strategy is robust with respect to the sequence of the loads within inbound trailers. The main benefit of the monomaniacal strategy is that it can be readily implemented without requiring changing the door assignment or incurring in any investments.
Progress in Material Handling Research
Carlo, Hector J. and Santiago-Montano, Stephanie, "A Practical Collaborative Material Handling Strategy for Cross-docks" (2018). 15th IMHRC Proceedings (Savannah, Georgia. USA – 2018). 11.