Multi-mode multi-skill personnel scheduling in Roll-on/Roll-off terminals

This case study evaluates multi-mode multi-skill personnel scheduling in Roll-on/Rolloff (RoRo) terminals, focusing on the loading of vehicles onto a RoRo ship by internal and external personnel. In this personnel-intensive loading, vehicles in parking areas of the RoRo terminal are grouped into prioritized batches and driven by teams through a ramp onto the decks of the RoRo ship. The hierarchical objectives are to load the batches so that the highest possible sum of priorities is achieved and the lowest possible number of external teams is used. We formalize the problem by identifying the essential components of decision making and by formulating a Constraint Programming (CP) model. Furthermore, we quantify the problem by comparing the objective values of different multi-skill allocations, a two-stage optimization, and a human planner with those of the CP model. Specifically, we evaluate the resilience of multi-skill allocations of internal teams to changes in those of external teams. Moreover, a two-stage optimization improves the resilience of decision making by increasing the operational flexibility. Our findings on manual personnel scheduling by a human planner indicate that decision support systems improve the loading. This case study not only contributes to the theoretical understanding of personnel scheduling in RoRo terminals, but also offers managerial implications for RoRo terminal managers to achieve improvements and resilience in their real-life personnel scheduling.