Labour fatigue constraints in Capacitated Arc Routing

Abstract

Municipal waste collectors have limited physical capabilities because of task related fatigue factors. However, minimal attention has been paid to fatigue and its recovery in the Capacitated Arc Routing Problem (CARP), despite their signi cant impacts on collection performance. To understand the dynamic impacts of workers' physical constraints on collection performance, we propose three models. The rst model is an acute-physicalcardiac fatigue model that quanti es the work pulse rate of the workers as a function of work rate. The second is a transportation-capacity (TC) model which determines the total amount of bins that can be serviced in a single shift by a collection crew for both the without-fatigue and with-fatigue states. Lastly, a service time model was developed, which takes the fatigue model, TC model and an arbitrary collection route as input. The service time model determines as output, the total collection time and how the labour fatigue changes throughout the route. The proposed models have the potential to decide alternatives for waste collection. That is, to do better route planning and to develop better routes. This will secure high productivity without compromising workers' health and safety. Ultimately, the proposed models highlight and address the research gap of the CARP with respect to human factors, speci fically, labour fatigue.