Integrating a software architecture-centric method into object-oriented analysis and design

The choice of methodology for the development of the architecture for software systems has a direct effect on the suitability of that architecture. If the development process is driven by the user's functional requirements, we would expect the architecture to appropriately reflect those requirements. We would also expect other aspects not captured in the functional specification to be absent from the architecture. The same phenomenon is true in development approaches that stress the importance of systemic quality attributes or other non-functional requirements; those requirements are prominent in the resulting architecture, while other requirement types not stressed by the approach are absent. In other words, the final architecture reflects the focus of the development approach. An ideal approach, therefore, is one that incorporates all goals, expectations, and requirements: both business and technical. To accomplish this we have incorporated, into a single architectural development process, generalized Object-Oriented Analysis and Design (OOAD) methodologies with the software architecture-centric method, the Quality Attribute Workshop (QAW) and Attribute Driven Design (ADD). OOAD, while relatively intuitive, focuses heavily on functional requirements and has the benefit of semantic closeness to the problem domain making it an intuitive process with comprehendible results. Architecture-centric approaches, on the other hand, provide explicit and methodical guidance to an architect in creating systems with desirable qualities and goals. They provide minimal guidance in determining fine-grained architecture, however. The integrated approach described in this paper maximizes the benefits of the respective processes while eliminating their flaws and was applied in a eight university, global development research project with great success. A case study from that experiment is included here to demonstrate the method.