Supporting the Exploration of Quality Attribute Tradeoffs in Large Design Spaces.

When designing and evolving software architectures, architects need to consider large design spaces of architectural decisions. These decisions tend to impact the quality attributes of the system, such as performance, security, or reliability. Relevant quality attributes might influence each other and usually need to be traded off by architects. When exploring a design space, it is often challenging for architects to understand what tradeoffs exist and how they are connected to architectural decisions. This is particularly problematic in architectural spaces generated by automated optimization tools, as the underlying tradeoffs behind the decisions that they make are unclear. This paper presents an approach to explore quality-attribute tradeoffs via clustering and visualization techniques. The approach allows architects to get an overview of the main tradeoffs and their links to architectural configurations. We evaluated the approach in a think-aloud study with 9 participants from academia and industry. Our findings show that the proposed techniques can be useful in understanding feasible tradeoffs and architectural changes affecting those tradeoffs in large design spaces.