TL;DR
The Architecture Definition Document is the qualitative view of the architecture solution. It packages the core architecture artifacts across business, data, application, and technology domains, and acts as the companion to the quantitative Architecture Requirements Specification.
What It Is
The Architecture Definition Document is a central ADM deliverable.
It acts as a container for the core architectural artifacts created during an architecture project and communicates the intent of the enterprise architecture.
It covers:
- all architecture domains: business, data, application, and technology
- relevant architecture states: baseline, transition, and target
- architecture rationale, justification, and major design choices
- the relationship between artifacts, views, and building blocks
Qualitative Companion
The Architecture Definition Document and Architecture Requirements Specification work together:
| Deliverable | View of the solution | Focus |
|---|---|---|
| Architecture Definition Document | qualitative | architecture intent, models, views, rationale, and structure |
| Architecture Requirements Specification | quantitative | measurable criteria that implementation must satisfy |
Simple memory hook:
- Definition Document explains what the architecture is and why it is shaped that way.
- Requirements Specification defines what must be measured or satisfied for conformance.
See also: Requirements Specification.
Typical Content
Common content includes:
- scope, goals, objectives, and constraints
- architecture principles
- baseline architecture
- target architecture
- transition architectures
- gap analysis
- impact assessment
- architecture models and views
- rationale and justification for the architectural approach
- mappings to the Architecture Repository, especially the Architecture Landscape
Artifacts and Building Blocks
flowchart LR BB["Building Blocks<br/>capabilities, services, actors, processes"] A1["Artifact<br/>process flow diagram"] A2["Artifact<br/>catalog or matrix"] A3["Artifact<br/>architecture model"] ADD["Architecture Definition Document<br/>deliverable container"] REP["Architecture Repository<br/>Architecture Landscape"] BB --> A1 BB --> A2 BB --> A3 A1 --> ADD A2 --> ADD A3 --> ADD ADD --> REP
Artifacts are views on the building blocks relevant to the architecture project.
For example, a process flow diagram may describe a target call handling process. The same diagram may also show related building blocks such as actors, systems, or roles involved in that process.
ADM Evolution
The Architecture Definition Document accompanies the architecture development process.
flowchart LR A["Phase A<br/>first version"] BCD["Phases B-D<br/>domain artifacts added"] F["Phase F<br/>finalized"] G["Phase G<br/>used by implementation projects"] PIR["End of Phase G<br/>possible post-implementation update"] A --> BCD --> F --> G --> PIR
- Phase A creates the first version.
- Phases B, C, and D complement it with business, data, application, and technology artifacts.
- Phase F finalizes it during migration planning.
- Phase G uses it to guide implementation projects.
- At the end of Phase G, content may be updated after implementation review.
Exam note
- The Architecture Definition Document is a central ADM deliverable.
- It is a qualitative view of the solution.
- It spans business, data, application, and technology architecture.
- It covers baseline, transition, and target architecture states.
- It contains architecture artifacts that represent views of relevant building blocks.
- It is the companion to the Architecture Requirements Specification.
- It is created and refined across the ADM cycle, then used by implementation projects in Phase G.