You checked the box for multiple float paths, hit F9, and now every activity has a number next to it. Path 1, Path 2, Path 7.
Most people look at that column once and never open it again. That's a waste, because it answers a question total float can't.
A float path is a chain, not a ranking
This is where people get it wrong.
Total float is a property of one activity. It says how many days that activity can slip before it hurts the finish.
A float path is a chain. It's a connected run of activities where each one pushes the next. Path 1 is the chain driving your completion date. Path 2 is the next chain behind it. And so on.
Here's why the difference matters. Take two activities, both showing 5 days of total float. Same number. Look at their float paths and one is on Path 2, the other on Path 6.
| On Path 2 | Slip it and you're a week from going critical. |
| On Path 6 | Slip it and almost nothing happens. |
Those are not the same risk. Total float alone can't tell you that.
The setting that changes your answer
P6 gives you two ways to calculate these, and they don't agree.
| Total float method | Groups activities by their float values. Fast, but the resulting "path" isn't always a real chain. You can end up with activities grouped together that don't actually drive each other. |
| Free float method | Follows the driving relationships. It traces what actually pushes what. |
If you want a path you can walk down and explain to a superintendent, use free float.
The setting nobody configures
By default, P6 calculates float paths back from the project finish.
Your contract date is usually not the project finish.
It's substantial completion. Or TCO. Or beneficial occupancy. There's often demobilization, punch list, and closeout sitting after it, carrying their own float.
Set the float path ending activity to the milestone in your contract. The paths change, sometimes a lot. And now they're pointing at the date that actually costs you money.
What to actually look at
Once the paths are right, don't just read Path 1. Read the gaps between the paths.
Look at the total float on each:
Everyone reports the second one as "we have one critical path." You don't. You have four, and they're all about to declare themselves at the same time. One bad week of weather and every one of them goes critical together, from four different directions.
That schedule is fragile and the float column alone never says so. It's the same trap as high float: the number looks fine and the structure isn't.
Quick version
- Float path is a chain. Total float is one number. Different questions.
- Free float method if you want a path you can explain out loud.
- Point the paths at your contract milestone, not the project finish.
- Read the spacing between paths, not just Path 1.
- If the paths are bunched, you don't have a schedule problem yet. You have one coming.
See how separated your paths really are
Grupo AE — Schedule Intelligence reads your Primavera P6 file and runs Float Path Analysis: how separated your near-critical paths really are, measured against the milestone you choose. Plus the full DCMA 14-point result and a 0–100 quality score. Takes seconds.
Also see the schedule quality checklist.