After completion of a software development project, a suitable verification of the results is neces-sary in order to anchor this conviction in the consciousness of all participants. In general the verification of software results– beside reviews – is done by testing. Testing is a tool of the Quality Management and serves the quality assurance. The goal is to guarantee the product maturity to meet the business requirements. Therefore the quality measurement metrics defined in ISO/IEC 9126 are taken as criteria (functionality, reliability, efficiency, usability, maintainability, portability and its subgroups; see Reference [3]). Testing should help to answer following questions: 1. Why? To ensure the required quality. 2. When? During the development until shipment. 3. What? The entire product from different viewpoints. 4. How? With appropriate methods for the different viewpoints. 5. Who? Members of the interest groups to any defined viewpoint.

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