In such cases, it is essential to base decisions and the planning of further evolutionary steps not only on economic considerations, but also on an in-depth analysis and understanding of the current state of the technical infrastructure and architecture. Also, user requirements and user-interaction aspects have to be taken into account at an early stage in the project, as they are often key drivers of change. When it finally comes to implementing the changes, the role of testing should not be underestimated. Testing is responsible not only for continuously reviewing the quality of the work done, but also for ensuring that the system as a whole still works as designed. Also, it provides valuable input for the further evolution of the system architecture.