Simulation model for aircraft line maintenance planning

This paper reports results of research that developed a computerized simulation model for the aircraft line maintenance department in Continental Airlines. The original AUTOMOD model that was created duplicated the maintenance operations at Continental´s major maintenance station at Newark. Modeling the day-to-day maintenance activities lead to the development of enhanced staffing models and a better understanding of resource requirements on a daily basis. This study had immediate and practical application as well as advancing an important frontier in operations research. Simulation modeling was effectively used in the estimation of technician requirements on a subshift basis. Simulation modeling generated performance measures, like technician utilization and work overflow, which could not be estimated earlier. The model gave objective justification for simple solutions like staggered shifts and part-time labor, which can meet resistance in a workforce. Simulation offers a viable tool for studying the impact of changing flight schedule on system parameters, like technician requirements. The optimization studies showed that changing the shift schedule could greatly enhance the efficiency of the existing system by spreading the workload more uniformly across shifts. Simulation, especially stochastic simulation, has advantages over mathematical modeling, especially in situations where flows have an apparent randomness in their character. Airline maintenance operations, and many maintenance operations in general, are plagued by planning difficulties because failures seem random at high levels of analysis, and/or because scheduling is tightly coupled with (and slaved to) other operations which are erstwhile irregular in their natures. Airline maintenance is one of the most important applications of maintenance in industry, as it has a profound impact on cost, customer satisfaction, and safety. This study applied stochastic modeling to flightline maintenance at an important airline, and illustrated the opportunity for improved maintenance management that only hints of its overall potential.