This content is excerpted from Service Oriented Architecture Field Guide for Executives (978-0-470-26091-3) with permission from the publisher, John Wiley & Sons. You may not make any other use, or authorize any others to make any other use of this excerpt, in any print or non-print format, including electronic or multimedia.

SOA Value Story
Ronald Schmelzer, of industry think tank ZapThink, describes four key benefits to SOA.[1]

1. Reducing integration expenses (both development costs and maintenance costs)
2. Increasing asset reuse (no need to re-invent the wheel each time)
3. Increasing business agility (the pace of business has changed, but few enterprises have)
4. Reducing business risk (both operational and compliance risk).

In the following sections, we will explore and illustrate each of these value propositions.

Reducing Integration Expenses

“If I had a dollar for every time that upper management asked me to cut costs…” — A CTO who is fond of irony

Cost cutting is a common demand that is levied on technology organizations. Consequently, each new paradigm within the industry (e.g., client-server, Web/n-tier, SOA, etc.) is pitched by some as a cost-cutting strategy. The trouble is that many enterprises attempt some grand enterprise-wide deployment rather than incrementally growing their SOA over time and incorporating lessons learned along the way. The fact is that, if properly implemented, SOA actually can reduce both development and maintenance costs. Use of loosely coupled, standards-based interfaces keeps integration costs low. By leveraging standard protocols, data formats, and interfaces, a great deal of traditional integration costs can be mitigated or even entirely avoided. Additionally, SOA’s push toward loosely coupled system integration allows for a reduction in time spent writing and ultimately maintaining custom integration logic. Some enterprises even see a reduction in middleware maintenance licensing fees by moving to standard Web Services interfaces rather than paying for a large stack of licenses in order to connect systems via various proprietary connectors and adapters.

Another way that SOA helps to keep costs low is by reducing the impact of making significant system and infrastructure changes. The multiple levels of granularity within SOA (recall the SOA stack examined in Chapter 1) facilitate changes to business processes and system use cases while minimizing the impact to the software baseline.

SOA reduces system maintenance and development costs associated with the deployment of new solutions by isolating components and systems through well-defined interfaces and proper architectural layering. To understand this better, consider Figure 1. In a standard enterprise environment, integration points between systems are tightly coupled:

• Vendor, platform, and/or language-specific bindings.
• Application-specific data formats are used.
• Application-specific application provider interfaces (APIs) are directly leveraged.

Figure 1: Tightly integrated enterprise environment