Modellbasierte Anforderungsspezifikation sicherheitskritischer ...

Therefore an iterative-incremental approach, grouped into phases and subprocesses, is used,
with which the amount of concrete information grows step-by-step. Test and verification techniques
are used in each step in order to guarantee the correctness of the modeling work previously
carried out. The precondition for this is that a model is obtained as early possible, which is mature
enough for model execution to take place. This allows the application of automated test and
verification techniques and the simulation of the future behavior of the system. Within the scope
of this research an automated test case generation tool is used which allows the system behavior
to be made explicit such that it can be compared against the specified behavior. Optionally a
formal verification tool (based on model-checking) can be integrated, such that the requirement
model can be tested against safety constraints.
Through the course of this research a complete example model is used. This consists of a requirement
model for a level crossing safety system, which is oriented to the functionality of a real
safety system. The example model was developed to complete model execution capability and
the test methods described above were applied to it.
This showed that:
• model-based requirement specification is possible
• the chosen process model can be applied in practice
• and through the strict process orientation and the use of contemporary technologies it is
possible to improve the quality of requirement specifications.
The research also introduces the tools necessary for the individual steps and analyzes their
applicability. This leads to statements about a prototype tool-chain, with which the procedure
described can be implemented.
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