SOA is a simple concept focused on building modular IT systems out of components that can be shared and reused. This means that new applications do not need to be coded entirely from scratch, thereby accelerating the deployment of IT functionality and delivery of new business capability.

Service Oriented Architecture is an architectural approach to designing, building, and deploying information systems such that the system is created from simpler manageable building blocks, called “services.” Each service implements a discrete piece of business functionality. These services can then be mixed and matched to create entirely new applications or to deliver new business capabilities.

As a concept, SOA is not new. It is a product of the evolution of IT architecture and distributed computing concepts. However, it has only become a reality over the last few years because of the emergence of standards and maturation of supporting technology. The internet has played a significant role in the evolution of these standards, allowing services to interoperate globally within and across the boundaries of large and small organizations

Without standards, it would be difficult for services to communicate and interact with each other. Consequently, the aforementioned sharing, reuse and combination of services to create business processes on an as-needed basis would not be possible. A hi-fi stereo system is a good illustration of the importance of standards. Nowadays, one can safely buy and plug together a set of music components that comes from different technological concepts, manufacturers, resellers, retailers, and even regions of the world. One can even take a modern hi-fi component such as a Super Audio CD (SACD) player and plug it into a decades old amplifier and still make it work. The main reason this is possible is because stereo system manufacturers have agreed to build systems that adhere to common standards for both signal characteristics and content.

SOA Is About Business & Technology Alignment

At its core, service orientation is about aligning technology to efficiently and flexibly support the process and performance needs of the business. What does this mean?

Under conventional approaches to building IT systems, an application typically supports a pre-defined set of business requirements (such as sales orders or accounting). Whenever a new business need arises, organizations build or install new applications. This is highly inefficient especially when the different applications perform similar tasks and share the same data.

With SOA, services are designed so that they are discrete building blocks of a business process. As such, activities common across business processes can share one building block or service. For example, if “opening a checking account”’, “opening a savings account” and “opening an investment account”’ are three business processes, then a “monthly statement service” that prints the account activity in the last month can be shared across all three processes. Additionally, whenever a new business need arises, the supporting business process can be altered by simply replacing or revising selected services. Hence, SOA provides both IT flexibility and business agility.