Total Float

Dear

Please check in setting

Total float is less than or equal to  ( 0 )

From: https://forums.oracle.com/forums/thread.jspa?threadID=881584

There are two primary causes of negative float on  activities.

1. If a Must Finish By  constraint is assigned at the project level, this could cause negative float if the project cannot be completed by the constraint date. Check the Must Finish By date in Projects View, Dates tab.

2. If a mandatory constraint is assigned to an activity, this could cause negative float if the predecessor activities do not have enough time to finish. Run a schedule report to check for constraints.

Other possible sources of negative float:
 

• Out of sequence  progress. Correct the logic in the schedule or schedule using Progress Override or Actual Dates.
• Different Calendars on activities.
• External project(s) with constraints that have  relationship ties to the schedule. Check the Advanced
• Scheduling option "Ignore Relationships to and from  other projects"
• Backward leveling.  Reschedule to remove the leveling

My observation is that people tend to overlook the out-of-sequence and leveling reasons as well as outside links.

• After resource leveling negative float makes no sense, it becomes meaningless.
• How the out-of-sequence impacts schedule calculations is one of the reasons I believe all out-of-sequence events shall be fixed, even in the absence of resource leveling. You never know and might not notice if the impact is not obvious.

Regards,
Rafael

Hi Glecy Maranan 

In Addition to Mr.Rafael's Information

Check the activity which has the latest date and keep following the predecessor link,you can get info about the relationships and lag used which might be illogical

Cheer's

Shahul

One final point is that Float is measured in working days not calendar days, so a negative float of -200 days using one activity calendar, could equate to a negartive float of -40 days on another calendar.

Float is based on activity calendar.

Calendar 1 is for a 5 days work week and Calendar 2 is for a 7 days work week. It is the available work days  before it becomes critical that matter. What if for Activity 2 the following week have exceptions for all days?

Negative float is always caused by a constraint – you just have to find it…...  To understand how the calculations work in most scheduling tools see: http://www.mosaicprojects.com.au/PDF/Schedule_Float.pdf

Definitively Negative float is always caused by a constraint – you just have to find it…... 

The real challenge is when it is a constraint on the computations placed not by you but by the software like when solving out-of-sequence events. This can be further complicated if your project have outside links to jobs with out-of-sequence events that are driving nuts your schedule late dates computations and therefore your float values.

I would check for outside links to other projects. I had an issue before where I had an outside link that was causing the negative float. The project was actually deleted and still showed a link somehow, but after I found it and removed it the float corrected itself. If this is not the case, then from my experiences, it is most likely a constraint that is causing the problem.