A two-stage stochastic programming approach for multi-activity tour scheduling

This paper addresses a discontinuous multi-activity tour scheduling problem under demand uncertainty and when employees have identical skills. The problem is formulated as a two-stage stochastic programming model, where first-stage decisions correspond to the assignment of employees to weekly tours, while second-stage decisions are related to the allocation of work activities and breaks to daily shifts. A multi-cut L-shaped method is presented as a solution approach. Computational results on real-based and randomly generated instances show that the use of the stochastic model helps to reduce understaffing and overstaffing costs, when compared with the expected-value problem solutions.