Making Metaphors that Matter

The system metaphor was proposed in Extreme Programming as a lightweight alternative to more rigorous architecture practices, but many teams have trouble using metaphors effectively to improve team communication or evaluate a system's architecture. This is no surprise as few agile teams have had training in architecture practices let alone in how to create metaphors. In our experience this does not invalidate the metaphor, but rather shows that more guidance is needed in the proper use of metaphors. This paper outlines one team's positive experience using system metaphors in the development of a medium-sized, service-oriented, enterprise system. Specific guidelines for creating effective metaphors are presented along with concrete examples.