Andrés Felipe Porto 1,2, Amaia Lusa 2, César Augusto Henao 3, and Roberto Porto
Andrés Felipe Porto 1,2, Amaia Lusa 2, César Augusto Henao 3, and Roberto Porto Solano 1
1 Corporación Politécnico de la Costa Atlántica, Barranquilla, Colombia.
2 Universitat Politècnica de Catalunya, Barcelona, Spain.
3 Universidad del Norte, Barranquilla, Colombia.
Keywords: Labor flexibility, Annualized hours, Multiskilling, Overtime, Retail, Uncertainty.
1. Introduction
For industries, especially those in the service sector (e.g., call centers, hospitals, transportation, retail), maintaining a high level of service for customers while maintaining or improving their profits is not an easy task. In addition, the personnel planning is affected by external and unpredictable factors in their environment. As a sample of these factors, the uncertainty in demand (e.g., unexpected increases or decreases in the staff demand) and the unscheduled staff absenteeism stand out. These unpredictable factors produce mismatches between the staff supply and the demand for personnel, ultimately resulting in an increase in labor costs [1,2]. In the personnel planning problems, these mismatches between supply and demand are known as overstaffing and understaffing (i.e., staffing level higher or lower than required, respectively), and have been studied in the operations management area, for a long time [3,4]. The personnel planning problems constantly prompt industries and economic sectors to define new and better labor flexibility strategies [1,5]. In an uncertain context such as the one described above, the retail industry stands out for its constant and rapid growth worldwide, in addition to its intensive use of personnel [6,7]. Henao et al. [1] listed a set of restrictions that hinder proper personnel planning: (i) Contracts with fixed daily working hours, typically full-time; (ii) Legal restrictions, such as the regulated amount of weekly working hours, ordinary or overtime; (iii) Institutional restrictions, regarding shifts and their duration; (iv) Personal employee’s preferences; and finally (v) Single-skilled personnel, that is, they can perform a single task type.
2. The problem
Service industries have used traditional flexibility strategies for the personnel planning, such as varying lengths and number of shifts, as well as overtime. In addition, the literature on labor flexibility shows that there are typically four flexibility strategies that are individually implemented, these are: (i) Flexible working time, allows to relax the shifts length and the number of weekly/annual working hours of the employees [8,9]. (ii) Multiskilled staff, employees trained to work on multiple task types [1,7,10]. (iii) Teamwork, groups of employees who carry out the tasks together, and not individually [11]. (iv) Temporary workers, are those employees who are hired to work short periods of time in pressing situations [12]. Oriented to the service sector, and particularly for a retail store under uncertain demand, the problem consists in planning a flexible workforce, throu