Component-Based Development -- An Unexpected Benefit

by Richard T. Dué

Although the marketplace seems to be fascinated with the UML-RUP (Unified Modeling Language-Rational Unified Process) approach to object-oriented development, I believe that there are many reasons why UML-RUP is insufficient for component-based development. UML-RUP seems suited for "green field" projects. It provides no help in dealing with the development or with the reuse of components and designs. Furthermore, UML-RUP does not help with the project management activities of estimating, scheduling, monitoring, creating risk analysis, contingency planning, or creating cost benefit analysis of component-based development. Perhaps most important from the perspective of component-based development, however, UML-RUP ignores the responsibility-based design approach. UML-RUP is entirely driven by use cases. While use cases do an excellent job of documenting requirements from the user's point of view, developers need to know the responsibilities and capabilities of each component to be able to determine when and how they can be used and reused in systems.