Total Float Errors

Lalvarado

Hi all! I am working to show total float in a fairly robust project schedule. I've seen in other community posts that if you use lag ANR/OR have predecessors with a type other than Finish-to-Start, total float will not be accurate (i.e. large and negative numbers).

Can someone explain why this is so I can communicate the reasoning to a client? Additionally, if anyone knows a work around for this, please share!

Isaac A.

Hi @Lalvarado!

The TotalFloat() function calculates the number of working days that a task can be delayed without impacting the Project Finish Date. This is a dynamic formula that provides better insights into how changes to an individual task impact the entire project plan.

Sample Formula

=TOTALFLOAT([Primary Column]@row)

Syntax

TOTALFLOAT(value)

• Value: The row at which you want to calculate the TotalFloat function.

Example

=TOTALFLOAT([Task Name]@row)

This formula will return the TotalFloat for the given task at any specified row. If dependencies are not enabled, you may see an #INVALID COLUMN VALUE error. You can reference any column as the Value, as long as the row reference is the correct row to evaluate.

How It Works

TotalFloat will find the last date listed in your End Date column (or the column you have selected in your Project Settings as the End Date) and will calculate how many days tasks can shift while still meeting that target end date. If all tasks are linked via dependencies with no slack, your TotalFloat will be 0, indicating no wiggle room.

Important Note

If you use lag or have predecessors with a type other than Finish-to-Start, the TotalFloat might show large and negative numbers because these conditions can disrupt the dependency chain, leading to an inaccurate calculation of available float.

Related Functions

• Successors
• isCritical

I recommend checking this related community thread for more insights: TotalFloat Calculation and the TotalFloat Help Article for more details.

I hope this information helps!

Cheers,

Isaac.