DETAILING OUR EXCELLENCE IN OPTIMISATION

CREWS is equipped with powerful optimisers capable of obtaining optimised solutions for large and very large scheduling and rescheduling problems

• Duty scheduling
Schedules more than 70 000 tasks in more than 5 000 duties of different staff bases, satisfying more than 3 000 global constraints (e.g. maximum number of duties per base, maximum average duty duration per base, maximum percentage of night duties per base)

• Duty rescheduling
Reschedules more than 10 000 tasks in more than 1 000 duties while preserving original sign-in and sign-out times and obtaining highly optimised solutions

• Roster scheduling
Schedules more than 1 500 duties in more than 300 lines of multiple cyclic rosters

• Short-term scheduling
Schedules or reschedules 100 individual calendar schedules for a period of 30 days, which means allocating or reallocating 1 000 duties to those calendar schedules

• Real-time dispatching
Reschedules, in few minutes, more than 10 000 tasks in more than 1 000 duties while preserving original sign-in and sign-out times and obtaining feasible solutions

 

CREWS optimisers obtain solutions that optimise several goals at the same time. Popular, but sometimes conflicting goals are:

• Duty scheduling
Minimise number of duties, total working hours and number of times crew switch equipment

• Duty rescheduling
Minimise number of tasks left unallocated and number of changes with respect to the original solution

• Roster scheduling
Minimise number of roster lines, number of duties left unallocated and number of additional days off; maximise even distribution of workload among rosters

• Short-term scheduling
Minimise number of duties left unallocated, number of additional days off; maximise even distribution of workload among staff members, satisfaction of individual staff preferences and fairness of preference satisfaction among staff members

• Real-time dispatching
Minimise number of tasks left unallocated and number of changes with respect to the original solution

 

CREWS optimisers use state-of-the-art technology, namely column generation, Lagrangian relaxation, integer linear programming, dynamic programming, constraint programming and several metaheuristics.
They are integrated in a very user-friendly way that allows users to run several what-if scenarios just by changing parameter values.