Decomposition Diagramming

Contents 1 Applications 2 Procedures 3 Instructions 4 Example

A technique used to depict function decomposition. The purpose of function decomposition is to ease the comprehension and management of function information found in a business area analysis project. The technique of function decomposition represents the activities of a business area as a hierarchy of functions and processes. The hierarchy is independent of organizational structure, existing or planned, and of current procedures. It acts as a basis for verifying the understanding of what the enterprise is about and for planning more detailed analysis.

Applications

• To facilitate understanding and management of business area function information.
• To define and graphically depict the hierarchy of functions and processes within the enterprise.

Procedures

1. Identify high level functions.
2. Identify component processes.
3. Depict graphically as in the following example to show hierarchy and sequence of functions and component processes.

Instructions

Decomposition diagramming and dependency analysis techniques can be used to produce a process model, the second component of the information architecture. (See Dependency Analysis.)

The decomposition diagram, along with the associated dependency diagrams, also forms a basis for system structure design and for procedure design, during later stages of business systems development.

Some activities will decompose further than others. Do not be surprised if some legs of the hierarchy are larger than others. Check for accuracy, using a dependency diagram. If there are activities in the diagram that are not connected to each other by dependencies, either directly or indirectly, then the decomposition is certainly incorrect. Modify as required.

Example