Glossary: Landscape, levels, and partitions

The Architecture Landscape, a representation over time

The Architecture Landscape is the architectural representation of the assets the enterprise uses or plans to use, at different moments. It therefore holds the description of the current state, of intermediate states, and of the target. It is not a classification mechanism: classifying from generic to specific is the role of the Enterprise Continuum.

Because a complete Landscape would be too large to describe in one piece, the standard offers two different ways to divide it: by levels of granularity and by partitions.

Example: an insurer keeps in its Landscape the description of its current applications, a Transition Architecture planned for year-end, and the three-year Target Architecture. The three descriptions coexist, each dated, and comparing them feeds gap analysis and then the Roadmap.

Three levels of granularity

Architecture Levels provide a frame for dividing the Landscape by level of detail. The standard retains three, from the most summarized to the most detailed.

• Strategic Architecture: a summary, formal description of the whole enterprise, giving an organizing framework for operational and change activity and a long-term, executive-level view.
• Segment Architecture: a detailed, formal description of areas of the enterprise, used at program or portfolio level to organize and align change.
• Capability Architecture: an architecture describing the abilities the enterprise possesses; it can be realized through successive increments.

Level or partition: two different axes

An Architecture Partition is a subset obtained by dividing an architecture to make it easier to develop and manage, for example by giving human resources to one team and logistics to another. The definition of levels says it explicitly: levels and partitions are distinct. The level answers 'at what detail?', the partition answers 'which piece, owned by whom?'.

Also watch out for Solution Architecture: it describes a focused business activity and its IS/IT support, but it is not one of the three Landscape levels. Likewise, a Capability Architecture is not a Business Capability: the first is an architecture, the second an ability of the business.