Why am I getting negative float on connections/links to an external schedule?

Hi,

Why would I be getting negative float on an activity that has different successor links, including one link to an external activity that has positive float. I made a what-if scenario by removing this external project and the negative float in my schedule dissappeared. I cannot make an analysis of the external schedule because I don't have access to see what's in there. One of the things that comes to my mind is that there might be some out-of sequence activities in that external file. Any ideas, comments, suggestions will be highly appreciated.

 

Thank you.

P
Paul Harris 👤 Member for 25 years 2 months

John

There are some calculation issue with the way that P6 calculates the Late Dates and I have experianced this issue when I have a relationship bewteen a Task on one calendar and an Successor Finish Milestone on another Calendar. I ended up with 600 days negative float on a two year long project once. We found by changing Finish Milestones to zero Duration tasks or Start Milestones the Late dates calculated differently and thus Total Float calculated differently.

I informed Oracle several years ago and I was assured it was on their fix list but the issue has not yet resolved!

This may give you a pointer as to what is causing your issue.

Also have you check for External Dates? These are constraint that are crete when you inport a project and do terrible things to a scheule if you do not know they are there!

Regards

Paul E Harris

BSc Hons, Certified Cost Engineer, PRINCE2 Practitioner

Managing Director and President

Eastwood Harris Pty Ltd, Australia

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