Loraine Lawson joined the discussion, and did a stellar job of summarizing some of the key SOA measurements under discussion into 12 succinct metrics to watch, drawn from the observations of Dan Foody, Dave Linthicum, Mark Little, Leo Shuster, and Jerry Smith. Here is Loraine's composite list of their key SOA metrics:
1. Return on investment (ROI) per service: "ROI per service can serve as an early indicator of your overall ROI."
2. Revenue Per Service: Not all services will generate revenue, of course, and this has to be taken into consideration.
3. Service Growth Rate/Reuse or Number of New Services Generated and Used as a Percentage of Total Services: "This metric can help you ensure you're reusing services when possible and not developing redundant services. It's also useful in calculating ROI for a service."
4. Business Agility or Mean Time to Service Development: "Measured in how long it takes for a service to go from the design stage to the deployment stage."
5. Mean Time to Service Change: The time it takes to change a service is another option for measuring agility.
6. Service Availability: This also reliability, measured in Mean Time to Failure (MTTF) and Mean Time to Recovery (MTTR).
7. Service Vitality Index: This “tracks the amount of revenue from new services over the last 12 months as a proportion of total service revenue.”
8. Efficiencies Associated with Service Reuse: "Efficiencies can be shown as time and cost savings associated with faster project deliveries when reusing services."
9. Integration Time Savings: "Since the integration cost for each ongoing or future project can only be estimated, a standard reuse factor can be applied to the service build cost. Eighty percent is the typical number used in these situations."
10. Related Opportunity Costs: The opportunities presented by SOA and service reuse need to be communicated across the organization. This requires investment in governance methodologies and associated technologies.
11. Cost Savings/Avoidance: "Service Cost Avoidance = Service Build Cost - Project's Service Integration Cost."
12. Reduction in Project and Maintenance Costs: "To calculate the entire project's cost avoidance amount, simply add the cost avoidance for all the services being leveraged. To forecast the total potential cost avoidance at any point of time, multiply the number of times each service is envisioned to be leveraged by its build cost and add it all together."