Glossary: work products, building blocks, and patterns

Artifact and Deliverable: the contractual criterion

An Artifact is an architectural work product that describes one aspect of the architecture: a catalog, a matrix, or a diagram. A Deliverable is also a work product, but it is contractually specified, then formally reviewed, agreed, and signed off by stakeholders. Merely being stored in the Repository does not turn an artifact into a deliverable.

Deliverables represent the output of projects. When a project ends, those in documentary form are usually archived, or moved into the Architecture Repository as a reference model, a standard, or a snapshot of the Landscape at a given date.

Building blocks: from logical to physical

A Building Block is a potentially reusable component that is combined with others to produce architectures and solutions. Its level of detail follows the progress of the work: a mere name at first, then a decomposition and a full specification.

The standard distinguishes two kinds of building blocks using the adjectives Logical (implementation-independent) and Physical (real-world, tangible). A logical architecture is realized through a physical architecture.

• Architecture Building Block (ABB): specifies, at a logical, supplier-independent level, the SBBs that are needed.
• Solution Building Block (SBB): physical, implementation-specific component that realizes all or part of one or more ABBs; there are business, application, and technology SBBs.

Patterns and Reference Models: guiding reuse

A Pattern is a technique for putting building blocks in context, for example to describe a reusable solution to a recurring problem. The standard sums up the difference this way: building blocks are what you use, while patterns explain how, when, and why to use them, and which trade-offs this implies.

A Reference Model is an abstract framework that helps understand the important relationships between the entities of an environment and develop consistent standards. It is not tied to concrete technologies, rests on a small number of unifying concepts, and provides common semantics, useful in particular to explain standards to non-specialists.