ForTeS – Optimisation of digital interlocking approval processes through an automated test platform and formal methods
The ForTeS project is developing a verification procedure for safe, interoperable interlocking subsystems in order to facilitate their cross-manufacturer integration and their approval.
The EULYNX consortium and the Europe’s Rail System Pillar are publishing the specification of the latest generation of interlockings called “digital interlockings”. This is a precise description of interfaces of the interlocking core with its adjacent systems and of the behaviour of several adjacent systems, for example of the point controller. An important goal is to empower infrastructure managers through the standardized modularization of the interlockings to buy subsystems from different suppliers.
Whereas meanwhile many suppliers develop and offer corresponding products, it stays difficult for infrastructure managers to actually use subsystems of different suppliers as part of the same interlocking. After all, the interoperability of the subsystems and the safe function of the interlocking composed thereof need to be proven – a task for which the supplier of the complete interlocking used to be responsible in the past. Proof and approval of combinations of subsystems from arbitrary suppliers pose a new challenge.
It is the goal of the ForTeS project to demonstrate an effective and efficient way for those. Basically, it is supposed to consist of two steps: The first one is about proving that the specification implies the necessary (interoperability and safety) properties. Therein, the project relies on the extremely rigorous method of formal verification. The second one is about proving conformity of a system implementation to the specification. Therein, the project relies on highly automated tests as an efficient and broadly applicable method; the certification test cases published by the EULYNX consortium serve as a basis.
Both steps taken together should enable proof and approval of subsystems, which is to be demonstrated as part of the project by means of a “simulated approval” of a point controller. A corresponding assessment report is supposed to become – besides the proof of specification properties and the developed test suite – the central result of the project. Thereby the project shall pave the way to reaching the goals of digital interlockings and consequently enable their fast and cost-effective rollout.
The DLR Institute of Transportation Systems contributes technically through the analysis of the specifications as well as through work on the complete test process – starting from the selection of test cases to the implementation/provision of the system under test and of the test lab to the test execution. Moreover, the project management is part of the institute’s contributions.
Project title:
ForTeS – Formalisation and Testing Platform for Digital Interlockings
Duration:
05/2025 to 04/2027
Further information:
This project is managed by the department:
