applications architecture or application architecture is one of several architecture domains that form the pillars of an enterprise architecture.An applications architecture describes the behavior of applications used in a business, focused on how they interact with each other and with users. It is focused on the data consumed and produced by applications rather than their internal structure. In application portfolio management, applications are mapped to business functions and processes as well as costs, functional quality and technical quality in order to assess the value provided.The applications architecture is specified on the basis of business and functional requirements. This involves defining the interaction between application packages, databases, and middleware systems in terms of functional coverage. This helps identify any integration problems or gaps in functional coverage. A migration plan can then be drawn up for systems which are at the end of the software life cycle or which have inherent technological risks.