Variable Crew Assignment Strategy

. Problem definition and model formulation.

In order to highlight the anomalies in flight line maintenance planning we use a medium size south Asian airline as an example and we call it airline “S” for documentation purposes henceforward. Airline “S”s flight line maintenance demand fluctuates throughout the day with significant peaks and off-peaks. At present, it has no fixed number of members in a job squad and different squads comprise members with different maintenance certifications. They are grouped on shift basis according to the available workload. All shifts are equally manned and shift maintenance manager decides the work assignments for work groups, which comprises several job squads. A job squad is expected to handle any type of

The day is divided in to three eight-hour shifts and the excess demand is covered through overtime where it again spans to eight hours. However, as per the aviation employee regulations if a crewmember works two eight-hour shifts consecutively it has several concerns. First, continuous work indulging of 16 hours without break is beyond the authorized threshold of 12 hours. Second, the employees is entitled for a 48 hours shift off which deprives his service for almost two days.

2.1 Variable Crew Assignment Strategy

In view of addressing the above drawbacks, we introduce a novel concept of varying labor utilization both numerically and duration wise. We name it “Variable Crew Assignment” (VCA) strategy and believe variable crew assignment combined with durable maintenance workload forecasting would produce better solutions for optimal crew scheduling problem. First, we propagate a common platform for the VCA strategy and incorporate it with a mixed integer linear programming (MILP) mathematical model. Then we move to validate the model through a case study regarding our sample airline “S”.

In this model, we try to vary the maintenance labor capacity through three variable channels. The three variables are the number of members in a squad, number of squads in a maintenance group during a specific job duration and the number

First, the maintenance demand fluctuation demands variable levels of labor utilizations throughout the day. Hence, this strategy varies the amount of job squads in a maintenance group during a specific job duration of the day. For an example, the number of crew deployed at peak demand is not essential at the off-peak hours. Therefore the number of maintenance job squads and in general, the number of employees are variably deployed to cater the fluctuating demand. Second, the variable number of squads is proportional to the number of variations in aircraft types so that the maintenance group is capable of satisfying the minimal maintenance demand during the shift. For an example if all servicing aircraft are alike during several shifts, then the job squad composition of the maintenance groups too would be same during those