I have zero knowledge of how the Dutch railway scheduling system works, nor of the nature of this failure, but SAP has been blogging recently about using Prolog for combinatorical optimization tasks such as the one that may be in use here or in SAP's Advanced Planning [1]. There are also well-known Prolog proponents from NL.

[1]: https://blogs.sap.com/2022/03/11/what-you-may-not-know-of-pr...