Heuristic Methods for Automatic Rotating Workforce Scheduling

Abstract

Rotating workforce scheduling appears in different forms in a broad range of workplaces, such as industrial plants, call centers, public transportation, and airline companies. It is of a high practical relevance to find workforce schedules that fulfill the ergonomic criteria of the employees, and reduce costs for the organization. In this paper we propose new heuristic methods for automatic generation of rotating workforce schedules. To improve the quality of each heuristic method alone, we further propose the hybridization of these methods. The following methods are proposed: (1)A Tabu Search (TS) based algorithm, (2) A heuristic method based on min-conflicts heuristic (MC), (3) A method that includes in the tabu search algorithm the min-conflicts heuristic (TS-MC) and random walk (TS-RW), (4) A method that includes in the min-conflicts heuristic the tabu mechanism (MC-T), random walk (MC-RW), and both the tabu mechanism and the random walk (MC-T-RW). The appropriate neighborhood structure, tabu mechanism, and fitness function, based on the specifics of the problem are proposed. The proposed methods are implemented and experimentally evaluated on the benchmark examples given in the literature and on the real life test problems, which we collected from a broad range of organizations. Empirical results show that the combination of the min-conflicts heuristic with tabu search can be used to solve this problem very effectively. The hybrid methods improve the performance of the commercial system for generation of rotating workforce schedules and are currently in the procees of being included in a commercial package for automatic generation of rotating workforce schedules.

Automated Shift Design and Break Scheduling

“…The shift design problem is a variant of the shift scheduling problem and has been first introduced in [12], [21], and [19]. The definition of this problem is given below (this definition is taken almost verbatim from [21] and [19]).…”

“…The definition of this problem is given below (this definition is taken almost verbatim from [21] and [19]). …”

“…The shift design problem described in this chapter has been first introduced in [12], [21], and [19]. In these works a tabu search based algorithm to solve this problem is proposed.…”

“…The first local search algorithm for the shift design problem has been proposed in [12], [21], and [19]. These initial works proposed different move types that were used for the exploration of the neighborhood.…”

“…Thus, if the search reaches a local optimum solution, the algorithm will not proceed any further, since it will not find solutions of better quality than the local optimum. To avoid this undesirable behavior, we apply an additional strategy known as random walk, which has been used successfully in algorithms for satisfiability problems [27], rotating workforce scheduling [22], etc.…”