Formal Based Tests for Conformity and Interoperability of Rail Systems

Abstract

This paper shows how to formalize different kinds of tests for a railway system. The common theme of the test scenarios is the goal of performing them in a reference laboratory. One line of tests concern the ETCS system, starting with specification conformity of the on-board unit. These tests are extended to address interoperability of different components of the ETCS system, and then to the validation of operational serviceability. The other line of tests aims to establish the interoperability of track-side equipment. The formalization concept for the ETCS tests starts with the conformity tests of the on-board unit, which itself is fully specified. Interoperability and serviceability address the unit's interaction with other equipment. This involves coping with systems in the test which are only partially defined. This is a feature of even more importance in the treatment of track-side interoperability. Overall, it is shown how a variety of different techniques is needed to cope with the challenge of fully attaining meaningful test results.