The Architecture Definition Document is the deliverable container for the core architectural artifacts created during a project. The Architecture Definition Document spans all architecture domains (business, data, application, and technology) and also examines all relevant states of the architecture (baseline, interim state(s), and target).

The Architecture Definition Document is a companion to the Architecture Requirements Specification, with a complementary objective:

• The Architecture Definition Document provides a qualitative view of the solution and aims to communicate the intent of the architects.
• The Architecture Requirements Specification provides a quantitative view of the solution, stating measurable criteria that must be met during the implementation of the architecture.

Typical contents of an Architecture Definition Document are:

• Scope
• Goals, objectives, and constraints
• Architecture principles
• Baseline Architecture
• Architecture models (for each state to be modeled):
  • Business Architecture models
  • Data Architecture models
  • Application Architecture models
  • Technology Architecture models
• Rationale and justification for architectural approach
• Mapping to Architecture Repository:
  • Mapping to Architecture Landscape
  • Mapping to reference models
  • Mapping to standards
  • Re-use assessment
• Gap analysis
• Impact assessment