Robust shift scheduling with discretionary rest breaks
研究在排班中允许员工自主选择休息时间对服务水平的影响，提出两阶段鲁棒优化模型和启发式算法，帮助管理者在员工自主权、服务水平和成本之间找到最佳平衡。
Shift scheduling is a critical task in workforce management, which consists of covering the staffing needs by feasible work shifts at minimum labor cost. Work shifts must include rest breaks according to national regulations and collective agreements, significantly impacting the expected Level of Service (LoS) provided to the customers. Therefore, managers tend to preserve the LoS by rigidly scheduling breaks at a centralized level. This affects the well-being of employees, who, especially in large organizations, require more discretion in choosing rest breaks to reduce work stress. This paper presents a two-stage robust optimization model with decision-dependent uncertainty to handle discretionary break assignment. This is a challenging problem both in theory and practice. We formulate it as a bilevel program and develop a tailored heuristic algorithm to find high-quality shift schedules for staffing patterns of several service systems. This methodology allows managers to assess the cost of discretion and to finely determine the best trade-off among discretion, LoS, and labor cost. • Centralized assignment of rest breaks causes stress to employees. • Discretionary breaks degrade the level of service (LoS) of standard work shifts. • In our two-stage robust model the employees discretion is a source of uncertainty. • We develop a methodology based on bilevel programming. • We compute shift schedules preserving the LoS from discretionary breaks.