Enterprise Architecture (EA) is often seen as too complex and academic to be of practical use in business settings. Sure, a formal vocabulary is unavoidable when describing a generic framework, but at the core of EA is alignment of IT strategy to the business strategy.
So let us start with some basic definitions. What is an Enterprise in the context of EA? It can be anything – a single business unit, a collection of business units or just a single department. Preferably it is the “entire” organisation, but in practice, it can be whatever the organisation in question wants to apply the EA rigour to. As for Architecture, I think the best definition is the one provided by TOGAF: “A formal descripton of a system, or a detailed plan of a system at a component level to guide its implementaton.”
So what then is EA? Again TOGAF gives a simple definition: “Enterprise Architecture provides a conceptual blueprint that defines the structure and operation of an organisation.” The intent of EA is to provids a strategic context for IT to evolve and support the business strategy.
Whether organisations formally embrace EA or not, the reality is that their IT is always evolving to its business strategy and needs. But instead of leaving this evolution to chance and point decisions, EA can provide a framework to avoid the “spaghetti” state. In this context, EA is often cited as analogous to town planning. A well planned town is a delight to visit and live in. On the other hand a collection of badly built (even with a few individually well designed) buildings often results in a mess that prevents the growth of a city from evolving into what it could potentially have been.
With this strategic intent, the EA becomes more of an investment than a cost. The EA outputs are no longer a necessary evil but valuable foundation for a sound enterprise. The business strategy is formally defined first (Business Architecture) which defines and drives IT Strategy (Application, Data and Technology Architecture). The principles and guidelines drive the solution designs in individual IT projects, reusing the building blocks already delivered. Also by following a formal architectural development method (like the TOGAF ADM) and a governance structure (Architecture Review Board), organisations further increase the chance of a coherent IT evolution that is not left to chance.