Documenting and Analyzing a Context-Sensitive Design Space

In most requirements engineering and software architecture documents, emphasis is placed on the chosen alternative. The discarded ones, and the arguments that led to a particular choice, are often not explicitly recorded and documented. This makes it difficult to retrace decisions and explore alternatives. We have developed a representation for capturing quality requirements and associated architectural solution fragments, called the Feature-Solution (FS) graph. We use the knowledge captured in the FS-graph to iteratively compose an architecture. This paper shows that when the knowledge in the FS-graph captures contextsensitive architectural knowledge, such as the concerns of different stakeholders, this representation can also be used to document and reason about architectural trade-offs. The result not only documents feasible architectures, but also the traces of design decisions that led to those architectures, which is a valuable asset during the further implementation and evolution of the system.