8.3.1 Characteristic features of architectural styles

The structural feature of an architectural style is related to the structure of software systems in the style. These features include:

• Constituent parts: What are the allowable kinds of components and connectors of the style? For example, in the pipe-and-filter style, components must be filters and connectors must be pipes.

• Control topology: What geometric form does the control flow for the systems of the style take? For example, in the main-program-and-subroutine style, components must be organised into a hierarchical structure.

• Data topology: What geometric form does the data flow for the systems of the style take? For example, in the batch sequential processing style, components are organised in a linear sequence structure that data are passed from one component to the next.

• Control/Data interaction topology: Are the topological structures of control topology and data topology substantially isomorphic? For example, for all systems in the batch sequential processing style, the topological structure from the control-flow point of view is identical to the structure from the data-flow point of view. In the main-program-and-subroutine style, from the control point of view,...