Article ID: | iaor20103442 |
Volume: | 61 |
Issue: | 5 |
Start Page Number: | 840 |
End Page Number: | 848 |
Publication Date: | May 2010 |
Journal: | Journal of the Operational Research Society |
Authors: | Cheng T C E, Ng C T, Tang G, Chen F, Chen Z-L |
Keywords: | personnel & manpower planning |
In this paper we consider a new transportation model, called the loader problem, which is frequently encountered by third-party logistics service providers in practice. It is a tactical staff-planning problem with the objective of minimizing the total labour cost of staffing a sufficient number of loaders on a given fleet of trucks that serve a given set of customer sites. We formulate the problem as an integer program and show that it is strongly NP-hard. We then consider two special cases of the loader problem that occur in certain practical situations, and propose polynomial and pseudo-polynomial time algorithms for solving these cases. We also propose a linear programming relaxation-based random rounding algorithm for the general problem and report the computational results of the algorithm.