Mathematical Problems in Engineering
Volume 2011 (2011), Article ID 209693, 18 pages
Research Article

Temporary Workforce Planning with Firm Contracts: A Model and a Simulated Annealing Heuristic

Industrial and Systems Engineering Program, King Fahd University of Petroleum & Minerals, Box 382, (KFUPM) Dhahran 31261, Saudi Arabia

Received 1 November 2010; Revised 7 December 2010; Accepted 8 January 2011

Academic Editor: Wei-Chiang Hong

Copyright © 2011 Muhammad Al-Salamah. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The aim of this paper is to introduce a model for temporary staffing when temporary employment is managed by firm contracts and to propose a simulated annealing-based method to solve the model. Temporary employment is a policy frequently used to adjust the working hour capacity to fluctuating demand. Temporary workforce planning models have been unnecessarily simplified to account for only periodic hiring and laying off; a company can review its workforce requirement every period and make hire-fire decisions accordingly, usually with a layoff cost. We present a more realistic temporary workforce planning model that assumes a firm contract between the worker and the company, which can extend to several periods. The model assumes the traditional constraints, such as inventory balance constraints, worker availability, and labor hour mix. The costs are the inventory holding cost, training cost of the temporary workers, and the backorder cost. The mixed integer model developed for this case has been found to be difficult to solve even for small problem sizes; therefore, a simulated annealing algorithm is proposed to solve the mixed integer model. The performance of the SA algorithm is compared with the CPLEX solution.