Enterprise SOA

How does ESA meet those challenges?

The key is the enterprise services themselves. They are the modular, reusable, flexible building blocks of ESA, which are already capable of meeting all of the challenges outlined earlier, provided they're assembled within an environment that is stocked with the appropriate development tools and honors the contract of the architecture.

Enterprise services are essentially pieces of processes. The pieces can be of any size and degree of functionality. One might be a utility function so small as to calculate only the time of day, and another might be large and complex enough to start the execution of a highly automated manufacturing process. But regardless of how large or how small they are, every enterprise service is designed to be a building block of a larger process, meaning they embody a host of attributes that enable them to meet the architectural challenges outlined earlier—the foremost of which is reusability. Precisely because they are building blocks, they were always designed to be recombined repeatedly, unlike previous generations of applications.

Because they were designed to participate in process orchestration, they were designed to be model driven. Instead of hardcoding services into applications, a new generation of modeling tools will assemble them. In order for a service to participate, it must be able to describe itself to the modeling environment so that its functionality can be adapted and added to the process and connected to ...