Enterprise Architecture: Why is it Important?
1. Holistic Approach
Individual divisions across the enterprise only address business problems in their vicinity; but the EA team will have holistic point-of-view and work towards addressing the problems across the enterprise.
For example, having a Credit Card Loan Processing System for a London division is addressing locale specific business demands but the EA team can align this solution at an enterprise level & might provide inputs to make it generic for making it reusable across the enterprise.
2. Consistency in Delivering Solutions to Business Problem
Once we have EA in place, a business solution can be delivered in more structured & consistent way. Established Reference Models for Business Demands
For example, if there is need to develop a Credit Check System, then enterprise reference model (if not available, then Industry Reference Model) will help in establishing consistent architecture for this solution.
3. Building Enterprise-wide Repository
Repository created in the process of establishing EA in an organization like Tools Repository, Architectural Artifacts Repository will encourage reuse & standardization across the enterprise.
4. IT Governance
EA goes hand-in-hand with IT Governance & collaboratively helps in establishing governance across the enterprise, which helps in building controlled & directed corporation. It acts like a framework for leadership, organizational structure, business processes, standards, practices, etc.
5. Defined Business/Technical/Information System Architecture:
Last but not least, as part of EA establishment in the organization, a clearly defined business, technical and information system architecture gets developed during the process. This also creates opportunity to business & IT people to come together & re-validate them.
Some of the popular EA frameworks are TOGAF, Zachman, FEA, Gartner, DoDAF & I have seen most of time there is a custom EA architecture extracting best of the practices/standards/tools from all of them.
Feel free to discuss it further in more detail.