What is Free Float and Why Should You Care?
Free Float is your project's buffer zone—the amount of time you can delay an activity without delaying the start of the next one. This metric is essential for project scheduling and timeline management.
Understanding Free Float helps you make informed decisions about resource allocation and task prioritization. It provides a cushion for unexpected delays and can prevent a domino effect that throws your entire project off track.
How to Calculate Free Float
The formula is:
[\text{Free Float (days)} = \text{Early Start of Successor (days)} - \text{Early Finish of Activity (days)}]
Where:
- Early Finish of Activity is when the current activity is expected to complete
- Early Start of Successor Activity is when the next activity is scheduled to begin
Calculation Example
Calculate Free Float with these values:
- Early Finish of Activity: 15 days
- Early Start of Successor: 20 days
[\text{Free Float} = 20 - 15 = 5 \text{ days}]
You can delay the current activity by up to 5 days without impacting the next task.
Example Breakdown
| Parameter | Value |
|---|---|
| Early Finish of Activity | Day 15 |
| Early Start of Successor | Day 20 |
| Free Float | 5 days |
Key Points
- Free Float is the time cushion available without affecting the next task
- Activities on the critical path typically have zero Free Float
- Negative Free Float indicates a scheduling conflict
Free Float vs Total Float
| Type | Measures |
|---|---|
| Free Float | Delay possible without affecting immediate successor |
| Total Float | Delay possible without affecting project end date |
Free Float is always less than or equal to Total Float. Understanding both helps you navigate project schedules effectively and keep your project on track.