Using feature modeling for program comprehension and software architecture recovery

The available evidence in a legacy software system, which can help in its understanding and recovery of its architecture are not always sufficient. Very often the system´s documentation is poor and outdated. One may argue that the most reliable resource of information is the system´s source code. Nevertheless a significant knowledge about the problem domain is required in order to facilitate the extraction of the system´s useful architectural information. In this approach feature modeling is introduced as an additional step in a system´s architectural recovery process. Feature modeling structures the system´s functionality and supports reverse engineering by detecting the relations between source code elements and requirements. Tracing these relations may lead to a better understanding of the program´s behavior and the recovery of various architectural elements. In this way, by providing a mapping between source code and features, the system´s feature model supports program comprehension and architectural recovery. The approach is developed as first part of a migration methodology towards a component-based architecture of legacy systems. Recovered information about features and architecture is collected in a repository to enable a refactoring as next step. The approach is currently applied in a large project for reengineering of an industrial image processing system.