Software engineering (SE) conference in 1968, Doug Mc Ilroy introduced the concept of software components during his keynote speech, "Mass-Produced Software Components." That components hold such an esteemed place in SE history should come as no surprise: componentization is a fundamental engineering principle. Top-down approaches decompose large systems into smaller parts-components and bottom-up approaches compose smaller parts components into larger systems. Since 1968, components have played a role in both SE research and practice. For example, components have been an immanent part of software architecture from its early days.2 In 1998, the In ternational Conference on Software Engineering introduced component based software engineering (CBSE) as a specific area within SE at the first workshop on CBSE.