Fixed-duration example: Program Management Level-of-Effort
Not a work item directly associated with the project product but one that supports it; its duration is based on the duration of the activity it is supporting.
Because duration is fixed:
- more units (i.e. more project managers) means more hours spent managing.
- less work means less units are required.
Increasing duration means the management supports the project longer and thus does more work.
For fixed-unit and fixed-work tasks revising either units or work changes the duration. They differ in what's recalculated when duration is changed.
Fixed-unit example: writing a report where the depth of the analysis is flexible.
Paul's analysis skills are so specialized only he can write Report X. If the duration changes then the scope of the report (i.e. the work) changes with it so he can finish on time.
Fixed-work example: painting a fence.
How long we have to paint the fence determines how many people need to work on it. Less time means a larger crew of painters.