Enterprise SOA

How does ESA enable consolidation and reuse?

Through the same set of attributes, actually. Because the enterprise services residing within ESA are loosely coupled, and the composition is not hardcoded, but rather, is assembled through process orchestration and modeling—they're just combinations and recombinations of underlying services, remember?—consolidation is simpler. Instead of having to migrate data and applications to a new, streamlined set of best practices running on a different platform, the process in question is already running on that platform; at this point, it's just a relatively simple matter of reconfiguring the underlying scenarios, business processes, and process steps.

Now—as someone once said, this is where the magic happens—those same enterprise services are able to unlock and recycle the functionality that used to go over the cliff. The investment in context now has a greater chance of supporting core activities. Because the process definition has been abstracted from the enterprise applications, it's possible to recombine the resulting enterprise services into new process steps and the like that can support business processes which are core. To understand what we mean, see Figure 2-4.

Figure 2-4. Consolidate and compose business processes on one platform

These recombinations are grouped together under the banner of composition. In the ESA universe, the IT department ...