One advantage of SOA is that it gives you a head start with using Cloud, and you at least have that reward for your SOA investment. But SOA is not just a jumping-off point for Cloud computing. When you implement Cloud, you also get to keep your SOA. Indeed, Cloud can strengthen your existing SOA and contribute directly to current SOA initiatives.
If you have a mature SOA, with an established SOA platform, you can look to SaaS providers for some of your services. This can be the best way of achieving the functionality that you need for the nine reasons listed for Cloud deployments―from agility and timeliness through to business continuity. If you want to provide new functionality quickly or if you are concerned about loss of service in case of natural disaster and the services you need are available on the Cloud, then your problem is solved.
Equally, if you do not have the resources to develop or support the services that you need, or if you want to experiment with new business offerings without taking a big investment risk, Cloud can be the answer. You can also, of course, consider using IaaS and PaaS in its current form, for the same reasons.
If you are setting up or extending your SOA platform, you should think about using IaaS and PaaS as the basis for that platform. But the real advantage will come with “SOA as a Service.” The cost and difficulty of establishing the SOA platform is often a major barrier to adoption of SOA. You can adopt a service-oriented approach without having an expensive platform, for example by “hard wiring” services instead of de-coupling them by using messaging, but you will not gain the full benefits of SOA in this way. It is difficult to justify a full SOA platform on the basis of a small project, and just as difficult to justify a large-scale SOA development without having done a small project first. Cloud can remove that barrier and avoid that dilemma by making SOA platforms instantly available and paid for per-use rather than by an up-front investment.
Cloud is in many ways the next logical step beyond SOA. SOA applies the service principle to application software within the enterprise. Cloud applies that principle at the infrastructure and platform levels, as well as the application level, and between enterprises, as well as within them.
SOA requires major investments in equipment, skills and culture change. The SOA skills and culture learned in the process will also help an enterprise to take advantage of Cloud. In return, Cloud will help the enterprise overcome the barriers of finance and risk that hinder adoption of SOA. In particular, “SOA as a Service” on the Cloud could dramatically accelerate SOA implementations and deployment.
Finally, Cloud is about what you use, and SOA is about how you use it. “What” is much easier to learn than “how.” An investment in SOA training will still pay off when you have Cloud―and don’t worry too much about the additional Cloud learning costs, it won’t take long for your people to be productive.
Chris Harding leads the SOA Working Group at The Open Group, an open forum of customers and suppliers of IT products and services. In addition, he is a director of UDEF Forum, and manages The Open Group’s work on semantic interoperability. He can be contacted at [email protected].