Enterprise SOA

How can ESA be addressed at a tactical level?

ESA is a topic with such a wide range and such depth in terms of its effect on IT that it can be difficult to understand where to start. You can find part of the answer by using offerings such as the ESA Adoption Program, explained later in this book, that provides approaches for understanding how ESA can help a business and for creating a long-term roadmap.

But on a tactical level—the level of today's project list—ESA can be pursued every day. To help understand how ESA can relate to almost every project, it can be useful to think of the five Cs of ESA. These levels are important, because you cannot just push a button and make ESA a part of your business. You must integrate it in steps.

Figure 1-20 shows the five tactical levels. The first is conceiving, which involves making sure you know what you want ESA to do. The next is consuming, the task of putting services to work in simple ways to attack projects that are easy to complete. The skills built into consuming services can support the next level, composing, in which more innovative and complex applications based on services are created. The task of composing applications generally starts with existing services, but if the job cannot be done with services already in the repository, then the next tactical level is required. Creating services is perhaps the most technically challenging level, in which you design and create new services by using a variety of development tools. Finally, ...