A cost-benefit framework for making architectural decisions in a business context

In any IT-intensive organization, it is useful to have a model to associate a value with software and system architecture decisions. More generally, any effort-a project undertaken by a team-needs to have an associated value to offset its labor and capital costs. Unfortunately, it is extremely difficult to precisely evaluate the benefit of "architecture projects"-those that aim to improve one or more quality attributes of a system via a structural transformation without (generally) changing its behavior. We often resort to anecdotal and informal "hand-waving" arguments of risk reduction or increased developer productivity. These arguments are typically unsatisfying to the management of organizations accustomed to decision-making based on concrete metrics. This paper will discuss research done to address this long-standing dilemma. Specifically, we will present a model derived from analyzing actual projects undertaken at Vistaprint Corporation. The model presented is derived from an analysis of effort tracked against modifications to specific software components before and after a significant architectural transformation to the subsystem housing those components. In this paper, we will discuss the development, implementation, and iteration of the model and the results that we have obtained.