In this project, Prover Technology provided interlocking software to GE under a turn-key supply. The purpose was to reduce the calendar time required to develop, validate and verify interlocking software for the 10+ interlocking systems of the Solna and Sickla light rail lines in downtown Stockholm. In this project, GE was responsible for defining the signaling principles, and Prover supplied interlocking software based on formalization of those principles and using the Prover iLock software tool suite for generation and checking of each application.
During the course of the project, the customer decided to change the hardware platform to a new platform called Tempo; since the Prover iLock tool suite is not tied to any particular target language, it was straight-forward to support the new Tempo target.
The solution Prover Technology used for the supply was based on:
- Formalization of signaling principles supplied by GE.
- Using Prover iLock for generation and checking of each interlocking.
- Sign-off safety verification based on Prover Certifier. The sign-off tool for Tempo provides independent verification that the revenue service Tempo code, including its compiled, binary image, meets the safety requirements.
The first revenue service installation of the new interlocking systems on Tvärbanan took place in 2013.