SISCOG

This project was done in the context of a partnership between SISCOG and Netherlands Railways (or NS, which is the main Dutch passenger railway operator) as a continuation of LUCIA I (see below).
It aimed at solving as fast as possible large-scale duty scheduling problems considering all real-world details.

The challenge was to efficiently solve in a single run for a single weekday the entire duty scheduling problem both for NS’ train drivers and guards with all real-world constraints (e.g. constraints limiting in each crew base the number of duties assigned, the average duration of the duties assigned, etc.).
This means handling problems that can go up to 11,380 train trips and 29 personnel bases.

The results were compared with previous solutions. All new solutions were feasible, which was not the case for all existing solutions, and they were between 0.12% and 2.84% more efficient than the previous ones, which were already optimised. Some of the solutions were obtained in less than 12 hours of running time.

Sophisticated Operational Research and parallel computing techniques were used to achieve these results.

This project was the result of a partnership between SISCOG and NS and aimed at developing an optimisation model capable of solving from scratch large-scale duty scheduling problems.

The challenge was to solve in a single run for a single weekday the entire duty scheduling problem for NS’ train drivers with reduced number of constraints (i.e. only constraints limiting the number of duties and average duty length per personnel base).
This means handling problems that can go up to 9249 train trips and 29 personnel bases.

The results were compared with previous solutions for several test cases. Solutions that are up to 3% more efficient than highly optimised solutions were obtained, all of them in less than 33 hours of running time.