Applying Iteration to the ADM

The graphical representation of the TOGAF ADM and the description of the ADM phases discretely in order, as shown in the TOGA Standard - Architecture Development Method, can be read to imply a deterministic waterfall methodology. This method of presentation is provided for the purpose of quickly communicating the basics of architecture development and the architecture development cycle. In practice, two key concepts are used to manage the complexity of developing an Enterprise Architecture and managing its lifecycle - iteration and levels. The two concepts are tightly linked.

The ADM supports a number of concepts that are characterised as iteration. First, iteration describes the process of describing a comprehensive Architecture Landscape through multiple ADM cycles based upon individual initiatives bound to the scope of the Request for Architecture Work. Second, iteration describes the integrated process of developing an architecture where the activities described in different ADM phases interact to produce an integrated architecture. In order to concisely describe the activity and outputs, this latter iteration is described in sequential terms. Third, iteration describes the process of managing change to the organisation's Architecture Capability.

Iteration to develop a comprehensive Architecture Landscape:

• Projects will exercise through the entire ADM cycle, commencing with Phase A Each cycle of the ADM will be bound by a Request for Architecture Work. The architecture output will populate the Architecture Landscape, either extending the landscape described, or changing the landscape where required.
• Separate projects may operate their own ADM cycles concurrently, with relationships between the different projects
• One project may trigger the initiation of another project
  Typically, this is used when higher-level architecture initiatives identify opportunities or solutions that require more detailed architecture, or when a project identifies landscape impacts outside the scope of its Request for Architecture Work.

Iteration within an ADM cycle (Architecture Development iteration):

• Projects may operate multiple ADM phases concurrently
  Typically, this is used to manage the inter-relationship between Business Architecture, Information Systems Architecture, and Technology Architecture.

• Projects may cycle between ADM phases, in planned cycles covering multiple phases

• Typically, this is used to converge on a detailed Target Architecture when higher-level architecture does not exist to provide context and constraint.
• Projects may return to previous phases to update work products with new information
  Typically, this is used to converge on an executable Architecture Roadmap or Implementation and Migration Plan, when the implementation details and scope of change trigger a change or re-prioritisation of stakeholder requirements.

Iteration to manage the Architecture Capability (Architecture Capability iteration):

• Projects may require a new iteration of the Preliminary Phase to (re-)establish aspects of the Architecture Capability identified in Phase A to address a Request for Architecture Work
• Projects may require a new iteration of the Preliminary Phase to adjust the organisation's Architecture Capability as a result of identifying new or changed requirements for Architecture Capability as a result of a Change Request in Phase H