10.2 The Architecture Landscape: Strategic, Segment & Capability Levels
Key Takeaways
- The three levels of the Architecture Landscape are Strategic Architecture, Segment Architecture, and Capability Architecture.
- A Strategic Architecture is a summary formal description of the enterprise providing an executive-level, long-term view for direction setting.
- A Segment Architecture is a detailed formal description of areas within an enterprise used at the program or portfolio level.
- A Capability Architecture describes the abilities an enterprise possesses and supports planning of capability increments.
- TOGAF architecture levels divide the landscape by granularity and are distinct from architecture partitions.
10.2 The Architecture Landscape: Strategic, Segment & Capability Levels
The Foundation syllabus asks you to list the three levels of the Architecture Landscape. In large enterprises many architectures exist at once — some broad and summary, some narrow and detailed. TOGAF uses levels to organize them into a coherent landscape.
The Architecture Landscape
The glossary defines the Architecture Landscape as "the architectural representation of assets in use, or planned, by the enterprise at particular points in time." In the Architecture Repository, the landscape is described as likely to exist at multiple levels of abstraction to suit different architecture objectives. An Architecture Level provides "a framework for dividing the Architecture Landscape into levels of granularity," and levels are distinct from architecture partitions.
Some architectures in the landscape address specific needs, others are more general; some address detail, others the big picture. Levels give a map of these different architectures so they can be related, governed, and kept consistent.
The Three Levels
| Level | TOGAF definition | How it is typically used |
|---|---|---|
| Strategic Architecture | A summary formal description of the enterprise, providing an organizing framework for operational and change activity, and an executive-level, long-term view for direction setting | Sets direction at executive level; provides context for all lower-level architecture |
| Segment Architecture | A detailed, formal description of areas within an enterprise, used at the program or portfolio level to organize and align change activity | Describes more detailed operating models for areas of the enterprise; organizes and aligns programs and portfolios |
| Capability Architecture | An architecture that describes the abilities that an enterprise possesses | Shows in more detail how the enterprise supports a particular capability; gives an overview of current capability, target capability, and capability increments, and lets work packages and projects be grouped within managed portfolios and programs |
A Capability Increment is "a discrete portion of a capability architecture that delivers specific value"; when all increments are complete, the capability has been realized.
The Applying the ADM document describes each level as an organizing framework: Strategic Architecture for operational and change activity and executive-level direction setting; Segment Architecture for operational and change activity, direction setting, and effective architecture roadmaps at program or portfolio level; and Capability Architecture for change activity and architecture roadmaps that realize capability increments.
Levels and the Architecture Continuum
Levels are one of two organizing concepts. The Architecture Continuum divides each level of the landscape by abstraction, from foundation elements to organization-specific architecture, which helps architects discover commonality and eliminate unnecessary redundancy. Together, levels and the continuum organize the landscape into related architectures with manageable complexity, defined groupings, defined hierarchies and navigation structures, and appropriate processes, roles, and responsibilities for each grouping. TOGAF adds that there is no definitive organizing model: each enterprise should adopt one that reflects its own operating model.
Developing Architectures at Different Levels
The ADM can be used to develop an architecture at any of the three levels. The levels relate as follows:
- Top-down direction: a Strategic Architecture sets the context, principles, and priorities for Segment Architectures; Segment Architectures set the context for Capability Architectures.
- Identification of lower-level work: an ADM cycle at a higher level often identifies, scopes, and prioritizes the architecture work needed at the level below.
- Bottom-up feedback: detailed work at lower levels can reveal constraints and opportunities that require higher-level architectures to change.
Because each architecture sits within a governance hierarchy, TOGAF describes two strategies for using the ADM across levels: develop architectures at different levels through iterations within a single ADM cycle, or through a hierarchy of ADM processes executed concurrently. In practice, architects usually blend the two to fit the Request for Architecture Work (Section 10.1).
Organizing the Landscape to Understand the State of the Enterprise
TOGAF lists four characteristics typically used to organize the Architecture Landscape:
| Characteristic | Meaning |
|---|---|
| Breadth | The subject matter area — generally the primary organizing characteristic; architectures are functionally decomposed into a hierarchy of subject areas or segments |
| Depth | Broader subject areas need less detail to stay manageable; more specific areas permit, and require, more detailed architectures |
| Time | For a given breadth and depth, the enterprise can create a Baseline Architecture and a set of Target Architectures stretching into the future; broader, less detailed architectures stay valid for longer |
| Recency | Each architecture view gains accuracy until it is approved, then loses accuracy if not actively maintained; recency can also organize historic architectures |
Using these criteria, architectures are grouped into the Strategic, Segment, and Capability levels. Within each level, practitioners also track architecture states — baseline, transition, target, and candidate architectures not yet approved to govern change.
Comparison Table
| Dimension | Strategic Architecture | Segment Architecture | Capability Architecture |
|---|---|---|---|
| Breadth | Whole enterprise | An area within the enterprise | A particular capability |
| Level of detail | Summary | Detailed operating models | Most detailed of the three |
| Primary users | Executives setting direction | Program and portfolio management | Teams planning capability increments, work packages, and projects |
| Typical ADM use | Direction-setting cycle | Program or portfolio cycle | Cycle supporting projects and delivery |
Scenario: A Utility Company
A utility's Strategic Architecture sets a ten-year direction toward smart-grid operations. A Segment Architecture for customer operations describes the operating model for billing, outages, and customer contact, and aligns the programs within that area. A Capability Architecture for "outage notification" details current and target capability, defines three capability increments (SMS alerts, app notifications, predictive alerts), and groups the related work packages into the customer operations program.
Common Exam Pitfalls
- Mixing up Strategic and Segment definitions. Strategic is the summary, executive-level, long-term view of the whole enterprise; Segment describes areas within the enterprise at program or portfolio level.
- Confusing levels with partitions. Levels divide the landscape by granularity; partitions divide architecture to facilitate development and management.
- Confusing Capability Architecture with Architecture Capability. The first describes enterprise abilities; the second is the ability to do architecture.
- Assuming only one level can be active. Architectures at all three levels coexist in the landscape and can be developed concurrently.
Which list gives the three levels of the Architecture Landscape?
Which level of the Architecture Landscape is used at the program or portfolio level to organize and align change activity for areas within an enterprise?
How does the TOGAF glossary describe the relationship between architecture levels and architecture partitions?
An architecture shows current and target states for a particular ability of the enterprise, defines capability increments, and groups related work packages into a program. Which landscape level is this?