In an enterprise, IT environment is a complex mix of heterogeneous systems, applications and hardware platforms. It is difficult to manage the respective functionalities of the various systems without having a collaborative environment or a common pool of functionalities to which the various systems can contribute in terms of services and can use the other systems services too. Organizations should encourage such system designs and can use the SAP NetWeaver as that collaborative tool. It is important to develop and deliver solutions in that mode only or else will be difficult for the existing and new systems to collaborate. The functionalities of the systems should be available in term of services. However, to handle enterprise-level, business-scale processes it is clear that Web services also need to be just as reliable, and maintainable as the current business software are. Enterprise Services Architecture (ESA) brings a business process perspective to the Web Services technology.
An Organization data generally spans over multiple systems and these systems provide various ways of manipulating that data. An Organization needs to find how the existing functionalities and processes can be broken down further to the services level and then should contribute these to the common pool. Take for an example, a purchasing process that can be broken down further to the various steps like
These steps will in turn serve as individual services and will be helpful for other processes too.
The next task for an architect would then be to take these individual pieces and join them through CAF. Packaged Composites Applications or xApps are such applications that come out through these business innovations being carried out by architects and managers.
CAF allows us to model this process from the vary basic level
1.) External Services represents the services of the external participating systems. These basically wrap RFCs and Web Services.
2.) Entity Services represent the data of the enterprise and allows defining of attributes, operations and permissions on it.
3.) Application Services represent the business logic and uses operations of entity, external and other application services.
4.) Guided Procedure in turn helps in modeling the entire business process using these application services.