3.3 Significance of the problem for component-based systems

Using components, component-based systems built from them, and component-based-frameworks like (Enterprise) Java Beans [Jav97] as an implementation basis for a wfms solves two of the problems mentioned above. The functionality of the wfms can be distributed more easily in an distributed and heterogeneous environment. Furthermore component-based frameworks improve the interoperability of wfms with legacy data and applications. They address the problem of interoperability between independently developed components like the wfms and legacy applications, which also evolve over time. However, the third obstacle for an enterprise-wide use of the present wfms, the lack of performance and reliability, can only be solved by using new, decentralized architectures. Therefore research in component-based systems should search for a new wfms architecture, allowing a fully distributed architecture, integrating the solutions of the other two problems provided by component-based systems.

Another point which highlights the significance of this problem for component-based systems is the observation that there is an analogy between wfms and composite applications based on components like Java Beans. Both are composed of applications from pre-fabricated components. Wfms connect several legacy applications together in an workflow and composite applications put together several components and connect them with events. To further investigate this analogy wfms and composite applications are compared in detail.

An aspect-oriented view as described for wfms in the problem section is also possible for composite applications. The functional aspect of composite applications describes their semantics and the composition of individual components. There is also a control aspect which can be realized by connecting the components by events and a data aspect by passing data between components. The operational aspect can be thought of as services offered by the components of the composite application. However, there is no organizational aspect, as there is no means to represent the relation to an organization within composite applications. The analogy between workflows and composite applications is also confirmed by the fact that workflows can be modeled by State- and Activity-Charts [WWWD96].