Evaluating Design Rationale in Architecture

Although architecture is often seen as the culmination of design decisions, design rationale is a suppositious child in architecture documentation. Many architecture frameworks and standards, like TOGAF and ISO/IEC 42010, recognize the importance, but do not offer any support in the rationale process. Recent initiatives have shown that simple means help in providing more rationale. However, there are very few studies that give evidence whether more rationale indeed leads to better quality. In this paper, we propose a non-invasive method, the Rationale Capture Cycle, that supports architects in capturing rationale during the design process. Through a controlled experiment with 10 experienced architects, we observe the effectiveness of the method in terms of design quality through different measures. The results of our experiments show that: (1) better rationale is strongly correlated with high quality, and (2) the test group with our proposed method outperforms the control group.