Sounds like a Dilbert cartoon ... I know ... but it highlights a big issue ― how to span the great divide between business and IT.
Enterprise Architecture is an attempt to span this divide. To effectively translate business strategies, goals and priorities to IT. More than that, Enterprise Architecture seeks to maximize business value from IT spending.
Enterprise Architecture is a fairly complex topic. As with any complex topic it is best explained with pictures.
1. Scope
At a high level Enterprise Architecture deals with at least 8 things.
2. Domains
Traditionally, Enterprise Architecture deals with many types of architecture.
3. Inputs
There are numerous inputs that an Enterprise Architecture needs to succeed.
4. Comparison with other architectural disciplines
Enterprise Architecture feeds into Solution Architecture and vice versa.
5. Lifecycle
Enterprise Architecture is an iterative process.
6. Enterprise Architects
To understand Enterprise Architecture it is useful to examine the typical job responsibilities of a Enterprise Architect.
7. Requisite Skills
What kind of person makes a good Enterprise Architect?

