The verification of the software is an important task in every software development. The appropriate fraction of the available resources to be allocated to this task depends on the risk caused by the software. For security-critical applications, such as control systems in the airplane and automotive industries, or vital satellite systems, a typical figure would be between 50 and 70%, while for standard systems only about 30% of the development budget must be set aside for software tests, to ensure that the functionality of the system is as specified.
DLR Simulation and Software Technology has a long experience with test and analysis procedures covering the complete software development process. DLR Simulation and Software Technology offers support in the planning, specification, automation and realization of the tests, as well as with the choice of suitable test tools. The fields of experience at DLR Simulation and Software Technology range from the test of graphical user interfaces and simulation codes to the test of embedded systems software.
In ongoing research projects DLR Simulation and Software Technology contributes to the advancement of test processes for embedded (critical) systems which have to fulfill particularly hard requirements in terms of functional and temporal correctness as well as integrity. Traditional test processes which aim at an in-depth coverage of paths or statements are generally insufficient in this case.
In addition, those systems must be tested together with their technical environment, so that the interaction can be checked between the control unit and the dynamics of the technical system. Typically these software are carried out in hardware-in-the-loop test environments. The disadvantages of this approach are high costs, low flexibility, as well as the required availability of special hardware. An alternative is the software-in-the-loop test approach. In the SiLEST project, funded by the German Federal Ministry of Education and Research (BMBF) and carried out in cooperation with the automotive industry, a test process and a test automation was developed which can be used for all in-the-loop test approaches. The SiLEST software allows testing the functionality of embedded software, together with the dynamic system surrounding it, at an early stage of the software development process already. The re-use of test cases throughout the complete development process and the test automation help to reduce the costs to a minimum.