A two-phase method for the shift design and personnel task scheduling problem with equity objective

In this paper, we study the Shift Design and Personnel Task Scheduling Problem with Equity objective, initially introduced by Lapegue, Bellenguez-Morineau and Prot (A Constraint-based Approach for the Shift Design Personnal Task Scheduling Problem with Equity, Computers and Operations Research 40 (10): 2450-2465). This problem, arising in the company Biotrial, consists in designing the shifts of employees and assigning a set of tasks to qualified employees, so as to maximise the equity between employees. We propose a natural two-phase approach consisting in first designing shifts and then assigning tasks to employees, and we iterate between these two phases to improve solutions. We compare our experimental results with existing approaches and show that our approach outperforms previous known results.