An MILP model for workload fairness and incompatibility in seafaring staff scheduling problem

Purpose - This paper treats the problem of scheduling seafaring staff inspired from a real case study, where the shipowner operates several vessel categories that require specific skills aiming to achieve a fair workload distribution and minimizing incompatibility between workers while meeting legal constraints, including requirements for days off and rest intervals between shifts. Design/methodology/approach - A mixed integer linear problem (MILP) formulation has been built to address the seafaring staff scheduling problem by integrating multiple objectives and constraints. The model’s performance is tested through experimental results across varying parameter adjustments. Findings - Our model was tested and validated using the XPRESS solver, and the results demonstrate its effectiveness in meeting the specified objectives and constraints. Notably, findings reveal that increasing the number of qualified workers leads to improved gains, until a certain threshold. Additionally, expanding the size of the workforce can result in longer execution times, specifically when incompatibility increases. Originality/value - The originality of this study lies in proposing a generic novel model that deals with maritime staff scheduling, incorporating worker incompatibilities and workload fairness as key objectives.