The modern industrial firm increasingly relies on software to support its competitive position. However, the uncertain and dynamic nature of today's global marketplace dictates that this software be continually evolved and adapted, to meet new business challenges. This ability – to rapidly...

Designers often seek modular architectures to better accommodate expected changes and to enable parallel development. However, we lack a formal theory and model of modularity and software evolution, which can be used for description, prediction, and prescription. According to Baldwin and Clark's...