In a WBS tree structure, the WBS elements can have parent-child
relationships. The possible parent-child relationships are defined as element
nesting rules. These rules are enforced during the WBS tree creation.
The WBS element nesting rules are described in the following table:
| Element |
Can contain |
| Program |
Project |
Milestone |
Summary task |
Task |
Change request |
Defect |
Issue |
| Root |
Yes |
Yes |
No |
No |
No |
No |
No |
No |
| Program |
No |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
| Project |
No |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
| Milestone |
No |
No |
No |
No |
No |
No |
No |
No |
| Iteration |
No |
No |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
| Summary task |
No |
No |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
| Task |
No |
No |
No |
No |
No |
No |
No |
No |
| Change request |
No |
No |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
| Defect |
No |
No |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
| Issue |
No |
No |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Notes:
- Under the WBS tree root node, you can only add programs and projects.
- Under programs, you can only create projects.
- Under projects, you can nest any WBS element.
- Under a milestone, you cannot nest an element.
- Under a task, you cannot nest an element.