All good, Zoltan.

Hi, Zoltan.

"When and activity has an actual finish there is no longer a need to forecast and early finish date becasue the activity is done."

You are right in that when the activity is done "there is no longer a need to forecast". But there may still be a need to analyze.

This is true especially if the actual finish was later than the original late finish, thus changing the as-built critical path. The activity (and its path) will have changed from having float to having drag. The amount of drag may not only have drag cost in terms of project overhead due to delay, but also its cause could become the focus of a court case regarding liability and liquidated damages.

Let's imagine that:

1. PATH A was the original critical path, and finished on schedule.
2. The Contractor was reponsible for PATH B, which originally had TF=5D, but slipped by 15D, delaying project by 10D.
3. The Customer was reponsible for PATH C, which originally had TF=10d, but slipped by 14D.

The ABCP should show that the drag of PATH B was not 10D but 6D, with appropriately adjusted liability. That requires accurately computing the drag of PATH B, which in turn requires computing the actual TF of the completed paths A and C. (And this is just another reason that Spider Project and Asta Powerproject are better than Primavera, because their computing drag is valuable both during planning and during ABCP analysis.)

Of course, I have no idea what a court would decide. (I suspect courts aren't familiar with critical path drag.)

Fraternally in project management,

Steve the Bajan

Zoltan, I hear what you are saying about an activity, once completed, having an ACTUAL start & finish date. But the definitional differences between early & late dates is significant.

When finished, the actual dates are indeed now the EARLY dates -- it can't get any earlier than when it actually was. But the LATE dates are not defined as "latest possible", but l"atest possible without delaying the project"! Therefore the ACTUAL dates are not the late dates -- the late dates are STILL what would have been the latest possible without delaying project. Therefore there is still ACTUAL (i.e., ABCP) float.

This is significant because critical path drag is potentially a VERY valuable metric in ABCP analysis -- and computing ACTUAL drag requires computing actual float. I know Primavera doesn't compute drag -- but for ABCP analysis, which Primavera is often used for, this is potentially a BIG problem! I'm not disagreeing that Primavera does what you describe -- just saying that, if so, either it needs to change OR it will fail to do ABCP analysis efficiently.

Fraternally in project management,

Steve the Bajan

BHadrash,

What are the MFP options you are using?  What happens if you leave "ending with activity" and "number of paths" as blanks?

Hi,

I have activities in "no float path" Section which has negative to positive float.

First ask youself what is float ? Float is the difference between the early dates and the late dates. These are calculated during the forward and backward passes. When an activity is 100% complete and has an actual start AND an actual finsh date there is no longer an early start or a early finish therefore there can be no float calculation.

Check to see if these activities are 100% complete.