Enterprise Architecture

Enterprise Architecture (EA) is a rigorous description of the structure of an enterprise, which consist of enterprise components, the externally visible properties of those components, and the relationships between them. EA could be an approach for business and IT alignment. The Open Group showed advantages of EA as below.

	Advantages
A more efficient IT operation	- Lower costs for software development, support, and maintenance - Increased portability of application - Improved interoperability and easier system and network management - Improved ability to address critical enterprise-wide issues like security - Easier upgrade and exchange of system components
Better return on existing investment, reduced risk for future investment	- Reduced complexity in IT infrastructure - Maximum return on investment in existing IT infrastructure - The flexibility to make, buy, or out-source IT solutions - Reduced risk overall in new investment, and the costs of IT ownership
Faster, simpler, and cheaper procurement	- Buying decisions are simpler, because the information governing procurement is readily available in a coherent plan - The procurement process is faster — maximizing procurement speed and flexibility without sacrificing architectural coherence - The ability to procure heterogeneous, multi-vendor open systems

An EA frameworks can be used to organize the structure and views associated with an EA. There are well-known and widely used EA frameworks, such as Zachman Framework, DoDAF (Department of Defense Architecture Framework) and TOGAF(The Open Group Architecture Framework).

Among those frameworks, Zachman framework was published first in 1987. It is originally made in 1987, and then updated and renamed in 1990s. It defines and views enterprise in structured view. It consists of tow dimensional classification matrix that is based on six communication question and five structured view. A below table shows "View of Zachman Framework"

	Data (What)	Function (How)	Network (Where)	People (Who)	Time (When)	Motivation (Why)
Scope	List of things important in business	List of Business Processes	List of Business Locations	List of Important Organizations	List of Events	List of Business goal & Strategies
Business Model	Conceptual Data/Object Model	Business Process Model	Business Logistics System	Work Flow Model	Master Schedule	Business Plan
System Model	Logical Data Model	System Architecture Model	Distributed Systems Architecture	Human Interface Architecture	Processing Structure	Business Rule Model
Technology Model	Physical Data/Class Model	Technology Design Model	Technology Architecture	Presentation Architecture	Control Structure	Rule Design
Detailed Representation	Data Definition	Program	Network Architecture	Security Architecture	Timing Definition	Rule Specification
Functioning Enterprise	Usable Data	Working Function	Usable Network	Functioning Organization	Implemented Schedule	Working Strategy