Website Upgrade Incoming - we're working on a new look (and speed!) standby while we deliver the project

Tips on using this forum..

(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?

(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.

Can a TF be greater than the duration of the project

3 replies [Last post]
Mon, 2008-10-20 04:34
richu rose
User offline. Last seen 32 weeks 2 days ago. Offline
Joined: 13 Feb 2007
Posts: 63
Groups: None
Dear Planner,

Can a total float for an activity be greater than the duration of the project.

For eg. In a 600 days duration project can an activity have a total float of 758 days.

Cheers,

Richu
Top

Replies

Tue, 2008-10-21 06:36
#1
Dieter Wambach
User offline. Last seen 7 years 31 weeks ago. Offline
Joined: 15 Jan 2007
Posts: 1350
Groups: Petro-Chem / Oil & Gas, TILOS
Richu
If you consider the algorithm to calculate float, the calendar is essential. If you default calendar is e.g. 5-days a week with 8 hours each and the project’s duration is 600 days. Now you have an activity in an early stage just related to the project’s end based e.g. on a calendar with 6 work days a week. The float will be calculated as from the project’s end and on basis of the activity’s calendar - about 700 days.

Recently main German EPC-Contractors had a meeting with Primavera and as this item is rather difficult to explain to management, we asked Primavera, to add an item where the float is calculated based on the project’s calendar.

I assume that other software for scheduling has the same problem.

Regards
Dieter
Top
Tue, 2008-10-21 05:03
#2
Gordon Blair
User offline. Last seen 6 years 43 weeks ago. Offline
Joined: 29 Jul 2005
Posts: 166
Groups: None
Yes you can, and it’s a bit silly, so I had to check, but it does kind of make sense.

Check the ’Project must finish by’ date. If this date is later than the early finish of the project, all of the activities will carry float. An early deliverable with no successors until the back end of the job could, in theory, have a Total Float in excess of the Total Duration of the job.

i.e.

Project A has a ’Must finish by’ of Day 500.

The total duration as scheduled is 300days.

As this finish is 200days early, every activity has a TF of at least 200days

The Frontage Sign can be completed by day 20, but is not required until day 270. The TF on the Frontage Sign therefore is (200 + (270-20)) 450 days - far in excess of the O.D. of the Project.

So, yes, it is possible.


But it’s silly, and you want to have another look at your Project dates and your logic.
Top
Mon, 2008-10-20 05:42
#3
Mike Testro
User offline. Last seen 18 hours 25 min ago. Offline
Joined: 14 Dec 2005
Posts: 4420
Groups: Building Information Modelling, Content Moderators, GPCCAR Editors
Hi Richu

In most forms of software the total float is measured from the last activity in the chain with an outgoing link to the end of the last activity in the programme.

Therefore it is not possible to have more float than the total contract period.

The situation can be created artificially if you have a milestone hanging out after the last activity with no incoming links.

Best regards

Mike Testro
Top