Section 3.17. How and where should I begin evolving toward ESA?

3.17. How and where should I begin evolving toward ESA?

The short answer is wherever there's a need and however that need can be served best. Because enterprise services are abstracted from the underlying systems of record, and because governance need not progress in a uniform manner, it's possible to begin deploying ESA anywhere within the enterprise at nearly any degree of complexity. Small implementations at the project level aimed at internal integration or creating a new interface for functionality abstracted from a wrapped enterprise application can coexist with enterprise-level efforts toward building the broader ESA platform. In fact, they already do.

Forrester Research surveyed more than 100 IT decision makers in late 2004 and discovered that many were already pursuing SOA adoption on multiple levels; internal integration was the most common use, but usually it was as part of a mixture that included external integration, multichannel applications, and strategic business transformation.^[*]

^[*] "Large Enterprises Pursue Strategic SOA," Forrester Research, Inc., April 5, 2005.

Early efforts to improve process efficiency incorporate internal integration and first attempts at wrapping application and orchestrating interfaces. As the architecture evolves, external integration in the name of process flexibility extends the scope of services beyond the enterprise to partners and customers, before achieving the more mature states of process innovation and business innovation, in which modeling is used to effect strategic change.

It's not necessarily a linear progression, however. Forrester also found that several participants in its survey were pursuing external integrations before internal ones. But there is a real risk that racing ahead at the project level to pluck the low-hanging fruit of integration will create compatibility conflicts later, once the platform has caught up. It may very well be that the proper path forward is the combination of a long-term, strategic plan for adoption centered on the Enterprise Services Repository, along with numerous short-term, ROI-focused projects designed to reap the benefits of ESA at each step of its evolution.