Designing the software architecture of a non-trivial system is not an easy task, and it requires highly skilled and experienced people. Over the years, researchers have proposed various approaches and tools to try and help software architects with this task. One category of such approaches and tools is that of so-called "design assistants". This term loosely includes any tool that takes as input some form of requirements for the system to be architected, and potentially an initial design, and interacts with the architect to help him/her concentrate on areas of the design that could use improvement to satisfy the requirements or could be optimized to improve quality or reduce costs. The idea is to assist the architect in a partially automated way.