General Nomenclature for Hierarchies

Analyzing Activities › Basic Activity Modeling Concepts › General Nomenclature for Hierarchies

General Nomenclature for Hierarchies

The business activities are as follows:

High-level activities (or functions)
Low-level activities (or processes)

A general nomenclature for describing any hierarchical or tree structure is useful when discussing process decomposition. The following illustration shows a typical Activity Hierarchy Diagram.

General Nomenclature for Hierarchies

The following table defines the term:

Term	Definition
Root	The root of a hierarchy is its highest level activity. In the previous illustration the single root is A. The root of an activity hierarchy for a CA Gen model must be a function.
Leaf	The leaves of a hierarchy are its lowest level activities. C, D, F, and G are leaves.
Parent	Any activity to which other activities are subordinate is called the parent of the subordinate activities. A is the parent of B and E; B is the parent of C and D; E is the parent of F and G. Any activity that is not a leaf is the parent of some activity.
Child	Any activity that is not the root is subordinate to another activity and is called the child of that activity. C and D are children of B; F and G are children of E; and B and E are children of A.
Sibling	Two or more activities that share a parent are called siblings of one another. C and D are siblings; F and G are siblings; and B and E are siblings.