Service-Oriented Architecture (SOA) is an IT strategy that organises the discrete functions contained in enterprise applications into interoperable, standards-based services that can be combined and reused quickly to meet business needs.

By organising enterprise IT around services instead of around applications, SOA provides key benefits:

• Improves productivity, agility and speed for both business and IT
• Allows IT to deliver services faster and align closer with business
• Enables the business to respond quicker and deliver optimal user experience.

A service is a module of logic, governed by a service level agreement (SLA) that can be accessed via a standards-based interface. Each service represents a piece of business or infrastructure functionality that maps explicitly to a step in a business or IT process. Services can be written from scratch, or composed by exposing modules of existing functionality from previously “siloed”/legacy applications.

SOA enables the enterprise to organise IT functionality into Services that meet the needs of the business, enabling companies to achieve the long-desired business goals of breaking down silos and focusing on the needs of the business and the customer.

SOA drives change in a number of ways

• Promoting the sharing and understanding of the whole business strategy, so that decisions are made with an enterprise level view and not just a line of business view
• Owning the overall SOA strategy of the enterprise so that appropriate emphasis is given to a multi-year roadmap
• Defining the architecture to be dynamic, responsive and standards-based
• Ensuring cost-effective delivery through identifying and optimising business processes that can be divided into re-useable shared services, and avoiding duplication of functionality by mining legacy applications for those services
• Deciding on the priorities for service development and deployment and choosing the increments and when they will be delivered
• Establishing the appropriate organisation and governance to ensure that processes, policies, and standards are followed
• Encouraging change and adoption through publicity and incentive setting
• Ensuring that appropriate measurements are put in place to provide constant cost-benefit analysis and provide a continuous feedback loop to interrogate the viability of the program
• Business processes become fully encapsulated by IT which enables IT to institutionalise the necessary measurement and accountability to the business.

Optimisation is not a one-off project but the execution of a multi-year road map through the SOA program. The initiative will require a number of cycles over time. The resulting standardisation of IT delivery to the enterprise through services is achieved in manageable steps in accordance with business goals, while reaping short, medium, and long-term benefits.