Architectural decision-making as a financial investment: An industrial case study

Context: Making architectural decisions is a crucial task but also very difficult, considering the scope of the decisions and their impact on quality attributes. To make matters worse, architectural decisions need to combine both technical and business factors, which are very dissimilar by nature. Objectives: We provide a cost-benefit approach and supporting tooling that treats architectural decisions as financial investments by: (a) combining both technical and business factors; and (b) transforming the involved factors into currency, allowing their uniform aggregation. Apart from illustrating the method, we validate both the proposed approach and the tool, in terms of fitness for purpose, usability, and potential limitations. Method: To validate the approach, we have performed a case study in a software development company, in the domain of low-energy embedded systems. We employed triangulation in the data collection phase of the case study, by performing interviews, focus groups, an observational session, and questionnaires. Results: The results of the study suggested that the proposed approach: (a) provides a structured process for systematizing decision-making; (b) enables the involvement of multiple stakeholders, distributing the decision-making responsibility to more knowledgeable people; (c) uses monetized representations that are important for assessing decisions in a unified manner; and (d) enables decision reuse and documentation. Conclusions: The results of the study suggest that architectural decision-making can benefit from treating this activity as a financial investment. The various benefits that have been identified from mixing financial and technological aspects are well-accepted from industrial stakeholders.