The sales force sizing problem with multi-period workload assignments, and service time windows

  • M. Angélica Salazar-Aguilar
  • Vincent Boyer
  • Romeo Sanchez NigendaEmail author
  • Iris A. Martínez-Salazar
Original Paper


This work introduces the sales force sizing problem with multi-period workload assignments, and service time windows. The motivation of the problem arises from a real life situation faced by a goods distribution company. The problem consists in determining the size of the sales force (i.e. the number of vendors to hire) and their daily schedules, within a planning horizon, to serve a set of customers in order to minimize the total nominal wage. There are different categories of customers and each customer has multiple time windows depending on the service day. Furthermore, the nominal wage of a hired vendor is determined by the most expensive category of the customers he serves. A mixed integer linear formulation and a heuristic are proposed for this problem. The performance of the heuristic algorithm is assessed over a set of instances adapted from literature. Computational results reveal the efficiency and scalability of the proposed procedure, providing a better tradeoff in terms of solution quality and running time than a commercial solver.


Sales force optimization Workload assignment Multi-period vehicle routing problem Personnel scheduling 



We thank CJOR reviewers for many helpful comments. This study was partially funded by UANL-PAICYT (Grant No. IT480-15), and by Consejo Nacional de Ciencia y Tecnología (Grant No. CB-2013/220811).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  1. 1.Graduate Program in Systems Engineering, Facultad de Ingeniería Mecánica y EléctricaUniversidad Autónoma de Nuevo LeónSan Nicolás de los GarzaMéxico

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