The maintenance and evolution of distributed, heterogeneous software components; including both legacy and green-field subsystems is described through a highly re-configurable architectural style. It is shown how this architectural style is realized through identification, separation and externalization of a formal specification of the manners of the application domain and its components. The approach is based on the notion of Enterprise Component (EC). An Enterprise Component is defined as an architectural pattern that is leveraged to provide a uniform mechanism for management of component boundaries between otherwise entropic systems consisting of multiple legacy systems coexisting with newer, object and component-based application programs. EC's are identified through a domain decomposition that includes mapping business architecture onto component-based software architecture. Extensions to current methodologies and architectural practices to support and realize such a style are presented.