In the town of Assen, in the North of the Netherlands, a large project is going on along the Florijn Axis to improve the accessibility of the city. Parts of this are a new and wider tunnel under the platforms, the parts of road tunnels underneath the tracks, a road tunnel under the forecourt of the station, parallel to the tracks. And a new railwaystation. Furthermore ProRail performs a number of projects for the tracks in Assen, like reducing the number of switches as an improvement of the reliability of the track, removing tracks which are redundant, adding a new 3rd track and raising the platforms to the new standard height.
Apart from the physical interfaces, it also is important that the throughput of travellers will not be interrupted during the construction activities.

There were a number of possible combinations of activities in various contracts, some of which have 2 clients, each taking care of a part of that specific contract. For each of these interfaces it was needed to specify them correct, so they could become part of the agreement between Assen and ProRail. The interface manager has identified the interfaces between all these sub-projects, including the risks that are related to these interfaces.