ANSWER

It should first be stated that there is some continued debate around the scope and definition of Enterprise Architecture.   Enterprise Architecture was born out of the world of Information Technology and comprises Application Architecture, Data Architecture, and Infrastructure Architecture.  This aligns with how many interpret the United States government’s definition of Enterprise Architecture which is to be an Information Technology function. 

Specifically, US Code Title 44, Chapter 36 defines Enterprise Architecture as “(i)a strategic information asset base, which defines the mission; (ii) the information necessary to perform the mission; (iii) the technologies necessary to perform the mission; and (iv) the transitional processes for implementing new technologies in response to changing mission needs [...]”.

However, as more professionals focus on the related topic of Business Architecture -- which covers the business organizational structure, business capabilities, business value streams or business processes, business knowledge, and finally the business strategy -- the need to clearly articulate the relationship between Enterprise Architecture and Business Architecture grows.  Based on the more historical definition of Enterprise Architecture, the two go hand-in-hand but remaine mutually exclusive of each other.  Historically, Enterprise Architecture was thought of as the Information Technology component which supported the Business Architecture. Recently, however, practitioners and leaders in the field have begun to broaden the definition of Enterprise Architecture to also include Business Architecture as a fourth sub-component, leaving Enterprise Architecture as the overarching concept.  

Based on this broadening of scope, Enterprise Architecture now covers:

• Business Architecture

• Data Architecture

• Application Architecture

• Infrastructure Architecture

• Cyber Security Architecture

Of course, there are a number of published Enterprise Architecture frameworks available including The Zachman Framework for Enterprise Architectures, The Open Group Architectural Framework (TOGAF), The Federal Enterprise Architecture, The Gartner Methodology, and more.  Depending on which framework you reference, the above 4 sub-architectures are sometimes named differently or divided/combined in a slightly different way.  Enterprise Architecture will remain an evolving discipline for years to come.

--
Chris Adams
LinkedIn Profile