TOGAF® Standard, 10th Edition · OGEA-101 Foundation · Quick revision
Baseline Architecture
Official definition — learn word for word
“A specification that has been formally reviewed and agreed upon, that thereafter serves as the basis for further development or change and that can be changed only through formal change control procedures or a type of procedure such as configuration management.”
This is the Chapter 4 definition of “Baseline” (§4.24); there is no separate “Baseline Architecture” entry. In the ADM, the Baseline Description describes the existing architecture.
Source: CC §4.24 · ADM §4.3.2
Memory aid
Baseline = today, agreed and locked. Change it only through formal change control.
Memory aid — not TOGAF wording.
In plain words
The agreed description of how things are today — the starting point for change.
Plain-English summary — not TOGAF wording.
Worked example
Today DUK runs three separate student databases. The agreed description of that as-is state is the Baseline.
Illustrative example (Digital University Kerala) — not from the Standard.
01Mind map — related concepts
Baseline Architecture
CHANGED ONLY BY
Formal change control / configuration management
PHASES B–D · STEP 2
Develop Baseline … Architecture Description
TO THE EXTENT
Necessary to support the Target
APPROACH
Baseline First or Target First
PHASE G · 11.3.5
Publish new Baselines to the Arch. Repository
NOT TO CONFUSE WITH
Target or Transition Architecture
Source: CC §4.24 · ADM §4.3.2, §11.3.5 · APPLY §2.4
02Baseline vs Target vs Transition
| Aspect | Baseline | Transition | Target |
|---|---|---|---|
| Chapter 4 | A formally agreed specification; changed only through formal change control (§4.24) | One state at an architecturally significant point in time (§4.83) | A future state of the architecture being developed (§4.78) |
| In Phases B–D | Step 2 — Develop Baseline Description | Identified in Phase E (9.3.10) | Step 3 — Develop Target Description |
| How many? | One per scope | One or more | Several future states may be developed as a roadmap |
Source: CC §4.24, §4.78, §4.83 · ADM §4.3.2–4.3.3, §9.3.10
03Baseline First vs Target First (APPLY §2.4)
Baseline Firstassess the baseline landscape to find problem areas and improvement opportunities
…suits whenthe baseline is complex, not clearly understood, or not agreed
or
Target Firstelaborate the target in detail, then map back to the baseline
…suits whena target is agreed at a high level and the enterprise wants to transition to it
If the baseline is broadly understood, higher value typically comes from focusing on the target first, then the baseline to the extent needed to identify changes.
Source: APPLY §2.4
04Where it appears in the ADM
Phases B, C, D · Step 2
Develop Baseline Business / Data / Application / Technology Architecture Description — to the extent necessary to support the Target.
ADM §4.3.2, §6.3.2, §7.3.2, §8.3.2
Phase G · Step 11.3.5
Publish new Baseline Architectures to the Architecture Repository.
ADM §11.3.5
Deliverable
The Architecture Definition Document contains the Baseline Architecture.
AC §4.2.3
05Exam traps
“The baseline must always be fully documented” → Only to the extent necessary to support the Target
“Always develop the baseline first” → Baseline First or Target First — depending on the situation
“A baseline can be updated informally” → Only through formal change control or configuration management
“Chapter 4 defines “Baseline Architecture”” → It defines “Baseline” (§4.24)
06Self-test — tap to reveal
Q1Define a baseline (§4.24).
A specification formally reviewed and agreed upon, serving as the basis for further development or change, changeable only through formal change control or configuration management.
Q2Which step in Phases B–D develops the baseline?
Step 2.
Q3To what extent is the baseline described?
To the extent necessary to support the Target.
Q4When does Baseline First suit?
When the baseline is complex, not clearly understood, or not agreed.
Q5When does Target First suit?
When the target is agreed at a high level and the enterprise wishes to transition to it.
Q6Where are new Baselines published in Phase G?
To the Architecture Repository (step 11.3.5).
Q7Which deliverable contains the Baseline Architecture?
The Architecture Definition Document.
Q8How can a baseline be changed?
Only through formal change control or configuration management.