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Software Architecture Guide

Application Architecture

Explanation

Section titled “Explanation”

Enterprise architecture is commonly split into four domains: business, data, applications and technology. Application architecture is one of these four. It deals with the choice of applications and the relationships between them. It does not deal with how one application is built inside.

TOGAF handles this work in Phase C (see “TOGAF Phase C: Application Architecture”). Its aim is to define the major kinds of application system the business needs to process its data and support its work. The phase decides which kinds of application are relevant to the enterprise. It is not application system design.

TOGAF describes applications as logical groups of capabilities, not as computer systems. Each group manages data objects and supports business functions. That ties the application layer to the data and business architectures.

TOGAF also defines applications without reference to particular technologies. This keeps the layer logical and free of implementation choices.

The organization’s application portfolio is kept as a catalog in the Architecture Repository.

Example

Section titled “Example”

A company lists the kinds of application it needs: one group of capabilities for handling orders, another for customer records. For each group, it notes which business functions it supports and which data it manages. It does not pick products or design screens. That detail belongs to the design of each individual system.

Trade-offs

Section titled “Trade-offs”

Keeping applications logical and free of technology gives a stable, high-level view across the portfolio. The price is that this view does not tell you how any one system is built. That needs separate design work.

Checks

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  • The document describes applications as logical groups of capabilities, not as specific computer systems.
  • Application descriptions do not depend on particular technologies.
  • The application portfolio is kept as a catalog in the architecture repository.
  • Each application is linked to the data it manages and the business functions it supports.
  • The enterprise-level application view covers choice of and relationships between applications, not the internal design of one application.
Section titled “Related”

Sources

Section titled “Sources”