SOA Success: Quantifying The Return on Investment of a SOA Project

Measuring SOA success is now a business requirement. The number of instances a shared service is reused is as an effective an SOA ROI measurement as any. Each reuse results in cost avoidance or reduction of building, maintaining, and operating a single-purpose service. In order to properly calculate ROI of shared services, some additional base metrics are needed:

• Costs to build/operate/maintain a shared service. This is the cost of having a shared service.
• Cost to build/operate/maintain a single-purpose service. This should be similar to that of a shared service if your SOA infrastructure is effective.
• Cost to use an existing service built by someone else. This is the cost incurred by reusing a service (the alternative would have been to build a single-purpose custom service). Controlling this metric is critical to SOA success. The reuse of a service is effectively an integration – and so your SOA needs to be structured to control the costs of integration.

Quantifying SOA Success: Which SOA initiative yielded a higher return on investment?

Shared-Service Consumers: A Valuable Metric

The number of shared service consumers (relative to total consumers) measures the breadth of SOA adoption. That is, it measures how well the "cultural shift" of SOA has permeated the organization. This is not directly correlated with overall SOA success, but is an important metric nonetheless.

Web Services Adoption

The number of web services created is not actually a measurement of SOA success. Instead, it primarily reflects the breadth of adoption of the underlying technology. In many cases, this metric can actually be used as an indicator of SOA failure. That is, if a large number of services exist, but few are reused, this may be an indication that your SOA initiative needs some revision.

Business Responsiveness

Compare the time it takes to change or add a feature to a non SOA-based application with a similar features change to a service.

In addition to the above methods of measurement, every project will have its own unique business justifications and associated measurements of SOA success. For example, exposing customer information via a service in order to create a self-service customer portal may be used to significantly reduce call center operations costs. These benefits will, of course, differ for each project. Even if you define a formal SOA pilot project, don't do this for the sake of moving to SOA – the project should provide value to the business.

A Note on Test Labs

One important pitfall to avoid in your SOA pilot implementation is limiting it to a test lab. Labs will provide your pilot implementation team with a safe place to learn the unique issues and benefits associated with SOA in each enterprise. However, SOA has significant impact on every stage and transition in an application's lifecycle (development, testing, staging, production, and especially subsequent versioning). It's important to gain real-world experience with the issues at these different stages of the lifecycle. These are among the most common causes of perceived failure of an SOA initiative. Unfortunately, a successful lab test outcome does not insure SOA success in the real world.

Anatomy of a Successful SOA Pilot Program

In summary, the keys to successfully implementing a SOA pilot include:

• Analyzing pilot requirements and scoping them for early success
• Creating a cross-functional team
• Choosing the right pilot
• Setting realistic goals
• Understanding deployment considerations
• Carefully quantifying the pilot from start to finish

For More Information

Learn about how to quantify SOA success. Download the free white paper, Web Services ROI: Maximizing Returns on Web Services Projects