Software quality is very hard to assess. It is commonly agreed ([143] [40] [144]) that comprehensibility, maintainability, portability, and testability are among the major factors. A high degree of conceptual integrity (which is a key to comprehensibility and maintainability) is enabled by the architectural concepts that have been described. Testability and reliability is also influenced by the architecture, and the main facility of VISTA for verification of these properties is VMAKE. Every night, the current versions of the framework and all integrated applications is checked out from a repository, a release version is built, transferred to each of the target platforms, built, installed and a full self-test is performed.
Organizational and human aspects (like unrealistic project plan, unqualified personnel, inability to track problems, weak project leadership, etc. - see, e.g., [53]) and not technical problems are often cited by managers as the major causes for software delays. The technical and organizational aspect, however, can not be entirely separated. Especially for long-term, incremental developments (as in the case of advanced, integrated CAD systems) the technical structure of the software will have an impact on the organizational structure and vice versa. One can counteract the organizational problems by choosing a software architecture which conforms to the organizational structure and takes into account the human aspects of the engineering process. In the case of VISTA, the application-framework architecture ideally conforms to the organizational structure of the engineering process.