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Free float last activity without successor ?

4 replies [Last post]
Floris Gering
User offline. Last seen 8 weeks 1 day ago. Offline
Joined: 30 Jul 2014
Posts: 27

A simple but confusing question for me:

The last activity in a chain has no successor (there is only the project end date) and this activity has some positive number as a Total Float value.

What should be the Free Float value for this activity ?

What you always read about the definition of free float is that is looks at the successor of an activity, but what if in this case, there is no successor ?

Should the Free Float value be 0 or should it be equal to the Total Float value ?

Replies

Floris Gering
User offline. Last seen 8 weeks 1 day ago. Offline
Joined: 30 Jul 2014
Posts: 27

Thanks guys for your answer. 
A colleague send me this screenshot in P6. I would have expected a free float value = 0 of the last activity. It seems however it depends on the last milestone, although it has no logical relation to this milestone ? 
For me completely vague.

2471
freefloatp6example.png

Floris Gering
User offline. Last seen 8 weeks 1 day ago. Offline
Joined: 30 Jul 2014
Posts: 27

Thanks guys for your answer. 
A colleague send me this screenshot in P6. I would have expected a free float value = 0 of the last activity. It seems however it depends on the last milestone, although it has no logical relation to this milestone ? 
For me completely vague.

 

2470
freefloatp6example.png

Patrick Weaver
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Joined: 18 Jan 2001
Posts: 372
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1. Good scheduling practice requires an end Milestone for the project. The last activity should have a successor (ie, the Milestone). and every activity should be able to trace a link form its successor to thsi Milestone.

2. If the Milestone has float, as Rafael says, the FF and TF are equal; the constraint acts as the successor.

3. This construct would also mean the critical path as a positive flaot value. 

For more on flaot calculations see: http://www.mosaicprojects.com.au/PDF/Schedule_Float.pdf 

Rafael Davila
User offline. Last seen 1 hour 7 min ago. Offline
Joined: 1 Mar 2004
Posts: 5229

A constraint can be considered as a successor event for purpose of calculating free float.  The activity in question can have a time constraint as well as an overall project finish date you set as a global constraint.

You can also set open ended activities as critical, this will make total and free float of the open ended activities equal to zero.

Also keep in mind float values will depend on calendars and float calculation settings depending on your software.