Duration is the total number of work periods required to complete an activity or work breakdown structure (WBS) component, typically expressed in hours, days, or weeks. It differs from effort, which refers to the total labor hours expended.
Key Aspects of Duration
- Measures Time to Complete Work – Tracks how long an activity takes.
- Excludes Non-Working Time – Calculated using available work periods.
- Can Be Estimated or Actual – Used in both planning and execution phases.
- Differs from Effort – Effort measures total work hours, while duration focuses on elapsed time.
Duration vs. Effort
| Concept | Definition | Example |
|---|---|---|
| Duration | The total time span required to complete an activity. | A software feature takes 5 days to complete. |
| Effort | The total work hours spent on an activity. | A developer spends 40 hours coding the feature. |
Example Scenarios
Software Development
A bug fix has a duration of 2 days, but since multiple developers contribute, the effort totals 16 hours.
Construction Project
Laying the foundation for a building has a duration of 2 weeks, considering available work shifts.
Marketing Campaign
A product launch event is planned over a 3-month duration, though the actual effort spent is spread across multiple tasks.
Why Duration Matters
- Improves Schedule Accuracy – Helps project teams estimate realistic timelines.
- Supports Workload Management – Balances tasks across team availability.
- Enables Critical Path Analysis – Identifies scheduling constraints.
- Helps Forecast Project Completion – Essential for planning and tracking.
See also: Effort, Work Breakdown Structure (WBS), Schedule Baseline, Time Management.