Critical Activity

This is most likely because you have a finishy on / finish on or before / mandatory finish date on your last activity, or a must finish by constraint on the project, which you current programme is unable to achieve.

The negative total float is the amount of time each of your activities must be brought forward by in order to satisfy this constraint. Removing the constraint will remove the negative float.

Presumably you have this constraint there for a reason. There are positives and negatives to using such constraints, and i would advise you research the matter a bit more before deciding wether to remove the constraint or not. -Constraints, particularly mandatory constraints, can have a number of important effects on your schedule and you need to understand what you are doing before using them.

Until such time as you feel confident that you understand their implications, I would advise removing the constraint(s), but this may not be an option if, for example, it is a contractual requirement.

I advise reading the Primavera help files, search for previous discussions in this forum, and setting up a dummy project to play around with the different types constriants to understand their effects on early dates, late dates, free float and total float; both for the constrained activity and also activities upstream or downstream of it.

Good luck,

G

Thank you, Mr Gary Whitehead for your Explanation. its acceptable in planning to

have all activities total float negative.

Not really, no.

negative float generally means one of two things. Either:

1) Your programme is unable to achieve the dates it needs to. -ie you have a required delivery date for part or all of the project which you have reflected with a constraint in your programme, but your current chedule will not meet that date. Typically these required dates will be in the contract, and often have financial penalties associated with missing them. So it's a big problem.

2) Your programme is poorly constructed. Either you have a constraint which should not be there, or should be a different type of constraint, or you have out of sequence (OOS) working which can also cause negative float. OOS is when eg you have a successor starting before its predecessor has finished. Either way, it's not acceptable to have a poorly built programme. Fix it, and the negative float will go away.

Hi Oyewole,

In addition to Gary's comments: It seems that you arranged most of your activities in a sequence.

Check in the project view the "Must Finish Date" and empty it.

Good Luck!

Dieter

Hi Oyewole

Also check your callendars to see if there are any work days in the last year of your project.

Best regards

Mike Testro