TOGAF® Standard, 10th Edition · OGEA-101 Foundation · Quick revision
Transition Architecture
Official definition — learn word for word
“A formal description of one state of the architecture at an architecturally significant point in time.”
One or more Transition Architectures may be used to describe the progression in time from the Baseline to the Target Architecture (§4.83 note).
Source: CC §4.83 · AC §4.2.3
Memory aid
Stepping stones across the river: each stone must deliver measurable value, and the gaps between stones need not be equal.
Memory aid — not TOGAF wording.
In plain words
A planned in-between state on the way from today to the target.
Plain-English summary — not TOGAF wording.
Worked example
Transition 1: admissions and fees share the new student record while exams still use the old database. Transition 2: exams migrated and the old databases retired.
Illustrative example (Digital University Kerala) — not from the Standard.
01Mind map — related concepts
Transition Architecture
ONE OR MORE
Only when an incremental approach is required
PHASE E · 9.3.10
Identify Transition Architectures
MUST PROVIDE
Measurable business value
TIME-SPANS
Need not be of uniform duration
TECHNIQUES
Definition Increments · State Evolution tables
NOT TO CONFUSE WITH
Work package (a set of actions)
Source: CC §4.83 · ADM §9.3.10 · TECH §6.3, §6.4
02Migration-planning techniques for Transition Architectures (TECH ch. 6)
| Technique | What it shows |
|---|---|
| Architecture Definition Increments table (§6.3) | Plans a series of Transition Architectures — lists projects and assigns their incremental deliverables across the Transition Architectures |
| Transition Architecture State Evolution table (§6.4) | The proposed state of the architectures at various levels using a taxonomy (e.g. the TRM); SBBs marked new / retain / transition / replace |
| Consolidated Gaps, Solutions, and Dependencies matrix (§6.2) | One of the bases for developing Transition Architectures (ADM §9.3.10) |
Source: TECH §6.2–6.4 · ADM §9.3.10
03Where Transition Architectures come from (Phase E)
9.3.3 Consolidate gap analysisresults from Phases B to D
9.3.9 Identify and group work packages
9.3.10 Identify Transition Architecturesclear targets along the roadmap; measurable value
9.3.11 Architecture Roadmapconsolidates work packages and Transition Architectures
Base them on the preferred implementation approach, the Consolidated Gaps, Solutions, and Dependencies matrix, the list of projects and portfolios, and the enterprise's capacity to absorb change (ADM §9.3.10).
Source: ADM §9.3.3, §9.3.9–9.3.11
04Where it appears in the ADM
Phase E · Step 9.3.10
Identify Transition Architectures — where the scope of change requires an incremental approach.
ADM §9.3.10
Phase E · Step 9.3.11
Consolidate work packages and Transition Architectures into the Architecture Roadmap.
ADM §9.3.11
Deliverable
The ADD contains the Transition Architecture: transition states plus Business, Data, Application and Technology Architecture for each.
AC §4.2.3
05Exam traps
“There is always exactly one Transition Architecture” → One or more — and only where an incremental approach is required
“Transition Architectures must be evenly spaced in time” → The time-span between them does not have to be uniform
“Transition Architectures are identified in Phase F” → Phase E, step 9.3.10
“A Transition Architecture is a work package” → It is a state of the architecture; a work package is a set of actions (§4.88)
“Do the hardest activities first” → Unless there are compelling reasons, implement difficult activities after those that most easily deliver missing capability
06Self-test — tap to reveal
Q1Define a Transition Architecture.
A formal description of one state of the architecture at an architecturally significant point in time.
Q2How many can there be?
One or more.
Q3When are they needed?
Where the scope of change requires an incremental approach.
Q4Which step identifies them?
Phase E step 9.3.10.
Q5What should each provide?
Measurable business value.
Q6Must the time between them be uniform?
No.
Q7Which table marks SBBs as new / retain / transition / replace?
Transition Architecture State Evolution table.
Q8Which deliverable describes each transition state per domain?
The Architecture Definition Document.