The discrete time break scheduling problem under fatigue and no preemption: solution methods and impact of work regulations

We address the discrete time break scheduling problem with no preemption when workers’ fatigueimpacts their productivity. We propose a Mixed Integer Linear Programming model to solve theone break problem to optimality, using a lexicographic approach where the production amount ismaximisedfirst,andthenthebreaklengthoveradiscretetimehorizon.WedevelopaVariableNeigh-bourhood Search algorithm to solve the multiple break problem. In addition to proposing efficientsolution methods to the problem, our incentive is to assess the impact on the production amountand on workers’ welfare of rest break regulations laid down in legislation or collective agreements.Weconductedanextensivesimulationstudytorepresentawiderangeofworkers’profilesdefinedinterms of fatigability and recovery speed. Simulation results show that regulations slightly affect theproduction amount whereas they allow for large improvements of workers’ welfare as long as breaksare optimised as a second objective. The production amount is also shown to be quite sensitive tothe break timing. Finally, multiple breaks can improve the production amount and workers’ welfarein many situations, which questions the widespread belief that endowing workers with a single shortbreak would optimise the production amoun