Introduction to Subject Area "Verification"

Over the last two decades the use of software in technical applications has dramatically increased. Almost all real-world systems are now embedded systems consisting of hardware and software components. Just think of modern automobiles; every new car comes equipped with computers that have many tasks in almost all parts of the car: fuel injection rates of the engine, airbags, anti-blocking systems (ABS) for brakes or the anti-theft device are some examples. With the use of software the complexity of such systems and therefore the risks associated with failures have increased too. Failure of the ABS can result in bad injuries or even fatalities. But cars are only the tip of the iceberg. There are far more critical embedded systems in our environment like air planes, high speed railways or nuclear power plants. Such systems must not fail. To assure safety thorough analysis is required. This can be done by the integration of techniques of modern software specification with engineering techniques the topic of this volume and the DFG focus area program 1064. In this part we will cover one such technique in particular: verification. Verification allows to rigorously prove that a certain property holds for a formal system model. Application of verification on critical embedded systems is the strongest analysis techniques available to ensure safety. However the task of formally analyzing a complex embedded system requires some effort and specialized techniques. This task can be split in three parts: