Exploring mathematical approximation for the time spans of transfer operations in parcel transshipment terminals

The parcel delivery industry (PDI) is a very labor intensive industry from the drivers of the pickup and delivery vans, to the unloaders sorters and loaders in the transshipment terminals. The labor efficiency is a key performance measure in the PDI. In this study the focus is on developing a framework for improving labor efficiencies in a parcel transshipment terminal. The objective is to minimize the time required to transfer parcels from inbound trailers to outbound trailers. This paper is an exploratory study to developing a framework for a solution approach to solve large-scale parcel hub scheduling problems (PHSP). A binary integer programming (BIP) model is proposed along with a branch and bound (BaB) algorithm with lower and upper bounds. The computational study shows that the BaB algorithm is able to generate solutions for small-size problems. The proposed BIP model sets the ground work for developing solution approaches to much larger size problems. © 2012 Elsevier Ltd. All rights reserved.