When we decided to start building the Siemens OpenSOA product line, it was pretty clear, we would have to deliver the first building block, our so called Symphonia framework, in a "rock solid" quality. As the framework is the runtime environment for all other applications, ervery error would directly influence all other applications. The quality of the architecture should not only be reflected as it is in the implemented system, but we wanted to be able to address it by a number of measures upfront: we defined non functional requirements and tests to proof them prior to the implementation of the affected parts instead of just testing them late in the process. We introduced test driven development to have running and tested software in every stage of the project. We conducted architectural assessments by internal and external auditors.

Nevertheless, it turned out lately that three factors were more important than all others: first of all architecturall quality is directly correlated to the degree your software satisfies the requirements. Secondly it is more important how well the architecture can be maintained and evolved than that you reached a good architecture at one point in time. Lastly you have a good portion of work to establish a development community which cares for quality as a matter of course and does not judge testing quality into the product as the last production step before delivery.