Bridging the gap between enterprise architectures and software architectures

摘要

The US Federal Agencies' Chief Information Officer Council in its guide to Federal Enterprise Architecture has defined an Enterprise Architecture (EA) to be "a strategic information asset base, which defines the mission, the information necessary to perform the mission and the technologies necessary to perform the mission, and the transitional processes for implementing new technologies in response to changing mission needs". An EA is an architecture, and hence by definition the EA serves as the "blueprint" for all information systems developed in an organization. In other words, we may consider the EA as capturing the information technology architecture of an organization including hardware, software, and networking standardizations, if any, that serves as the basis for all information systems developed within an organization. This viewpoint enables us to put EA in proper business perspective: the EA is derived from, and closely aligned with, the Strategic Enterprise Plan (SEP) of the organization where the SEP captures the high level business objectives and goals for the organization for the next 3 to 5 years. The Strategic Information Systems Plan (SISP), usually developed by the Information Systems business unit of the organization, is derived from the SEP, and prioritizes the information systems development projects that will be undertaken in the near term (next 3 to 5 years) by the organization that will help achieve the business goals of the organization set in the SEP. Any information system that is approved for development by the SISP usually, after another round of approvals by the executive sponsors, goes through the typical system development process whose initial phases include scope definition, problem analysis and requirements analysis.