The heart of the OIAm architecture methodology is formed by Building Blocks, which give the name to the Building Blocks Model. There are two sorts of Building Blocks available, Building Block Types and Building Block Variants.
Building Blocks represent single facilities. In most cases, those facilities are not used on their own, but are part of an infrastructure Product (or solution), that consists of a number of facilities that are providing this Product together. The structure of these solutions is called pattern. Two forms of patterns are defined in this knowledge system: