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Test and Certification of Railway automation and digitalization approaches (Rail 4.0)

Signalling Companies) have specified the ETCS by writing the SRS (System Requirements
Specification SRS [1]) and produce and deliver ETCS components for different railway
undertakings and infrastructure manager like Deutsche Bahn AG (German Railways) in Europe.
Before these may come into operation, their conformity with the SRS and their interoperability
has to be proven with lab tests as stated in previous section.
The issue 3.1.0 of the conformity test was specified by the Subset-076 Working Group (CEDEX,
DLR, INECO, MULTITEL, RINA). This specification includes the Hardware-in-the-loop tests of the
ERTMS/ETCS on-board equipment [1], the method of their creation [2] and the method of test
[3]. The specification of the reference lab architecture [4] completes the set of specifications.
Some of the UNISIG companies are implementing products or just finalising them. Some test
trips (field tests) have been performed successfully on the German pilot line Jueterborg-
HalleLeipzig. Currently the last steps of implementation of the tests are performed and the
latest version will be published very soon. The test target has been defined, generic test cases
have been specified and the method for the generation of the final test sequences has been
developed and realised. For the better understanding of the following sections these steps will
be discussed shortly in the following.

Figure 2: Relation between SRS and Test Sequence

The defined target of test sequences is to test each requirement of the SRS at least once. Firstly,
to organise and reduce the amount of requirements of the SRS, more than 200 features have
been identified. After this, the required positive and negative test cases have been created for
each feature. Totally more than 1700 test cases have been generated. Equivalent test cases for
different ETCS modes or levels have been merged to reach a first optimisation and reduction of
number of test cases. This means that test cases which are applicable for different mode-level
combinations are described as only one test case, if the feature was not dedicated to a specific
mode-level combination. Important is the testing of the feature itself. Just for clarification,
each ETCS mode is an operational state of the on board equipment and the ETCS level is an
overall degree of the usable functionality of ETCS. For the execution of the tests the test cases
are concatenated to 775 test sequences, which all start at the powering on of the on-board
equipment and end with the no power mode. The test subsequences are concatenated due
to their start- and end-conditions to reach a consistent sequence of system states. The test
sequences have been optimised to reach the lowest degree of redundancy of testing. Parts of
a test are only executed twice or more if they are needed to reach a state which has not been
tested yet. Up to the test sequences the specification is completely generic. At this stage the

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