Integrated simulation, heuristic and optimisation approaches to staff scheduling

This paper details a new simulation and optimisation based system for personnel scheduling (rostering) of customs staff at the Auckland International Airport, New Zealand. An integrated approach using simulation, heuristic descent, and integer programming techniques has been developed to determine near-optimal staffing levels. The system begins by using a new simulation system embedded within a heuristic search to determine minimum staffing levels for arrival and departure work areas. These staffing requirements are then used as the input to an integer programming model, which optimally allocates full- and part-time staff to each period of the working day. These shifts are then assigned to daily work schedules having a six-day-on, three-day-off structure. The application of these techniques has resulted in significantly lower staffing levels, while at the same time creating both high-quality rosters and ensuring that all passenger processing targets are met. This paper charts the development of this system, outlines failures where they have occurred, and summarises the ongoing impacts of this work on the organisation.