A3 architecture overviews : focusing architectural knowledge to support evolution of complex systems

Creating complex systems from scratch is time consuming and costly, therefore a good development strategy often chosen by companies is to evolve existing systems. The understanding that a company has about the impact change has on the system determines its ability to cope with system evolution. Reuse of knowledge and experience becomes therefore, essential. Complex systems are usually the result of a multidisciplinary team, which means that an effective way to capture, organize and present this knowledge, in a fashion that can be used by different disciplines and departments is crucial. Typically, some of this knowledge is present in the form of text documents. However, much of that knowledge is usually lost or hidden, especially in long-lived systems. This leads to unexpected problems that could be prevented if the company had reused the knowledge it already has. In this paper system evolution barriers are discussed, and a method to cope with them is provided. Some companies such as Toyota have already identified the advantages of using an A3 approach² to capture and share knowledge. We share this idea and take it several steps further. A method, based on the creation of 'A3 Architecture Overviews' is proposed to capture and share architectural knowledge. The method is the result of the work carried at Philips Healthcare MRI Group. We show that the proposed method to capture architectural knowledge provides an effective framework to support decision making when evolving complex systems.