early start and finish

Ahmet,

Ron Winter covered this issue in his 2009 AACE paper: http://www.ronwinterconsulting.com/Understanding_P6_Dates.pdf.

The short version - the CPM calculation includes all activities in the schedule.

P6 includes the data date in the calculation such that the early start of all activities equals the data date unless they are delayed by logical relationships.  For completed activities:

• Under Progress Override and Actual Dates , P6 over-writes the early and late dates with blank values as you expect.
• Under Retained Logic, P6 leaves the early and late dates unchanged.  This makes it easier to trace out-of-sequence completion logic, but for normal displays you will want to use the simple "Start" and "Finish" fields. 

once an activity is completed they are no longer considered in the forward or backward pass if you look at the dates you will see the letter A next the date this means that the activity has an actual start and or finish associated wiht it.  

Zoltan,

I'm not sure about progress override, but under retained logic all completed activities MUST be considered in both forward and backward passes (with RemDur=0).  Consider A->B->C.  If B is completed out of sequence and A has not yet started, the only way to properly schedule C (after A) is through B.  In this case, the forward pass finds the Early Start of B after the completion of A and (given a remaining duration of 0) its Early Finish is the same.  Now C's Early Start properly follows the Early Finish of the completed task B, i.e. after finish of A.

As I recall, P3 over-wrote the CPM early and late dates with the actuals and included the "A."  (And as a rule we included Early dates in all our layouts.)  Obviously that was a very different program. The "A" in P6 appears next to the new "Start" and "Finish" dates.  We include these on our layouts and keep the CPM dates hidden (mostly). 

Tom 

I guess from that perspective you are correct that it still considers it but does not show a NEW forecatsed start or finish date since it has been actulaized and it has an actual finish date (or an actual start date for start milestones) then the float is made blank.

When I build a schedule I always build it to early start and early finish dates in Oracle Database. When I go to update my project the items that are finished always return a blank in the early start and early finish dates. Is there a way to get the program to still show the dates that the activities started and finished on in the early start early finish columns? I would like to be able to use the early start and finish columns instead of having to add more columns to be able to look back and see the start and finish dates for an activity that has already been completed.

Thanks, 

When I build a schedule I always build it to early start and early finish dates in Oracle Database. When I go to update my project the items that are finished always return a blank in the early start and early finish dates. Is there a way to get the program to still show the dates that the activities started and finished on in the early start early finish columns? I would like to be able to use the early start and finish columns instead of having to add more columns to be able to look back and see the start and finish dates for an activity that has already been completed.

Thanks, 

Sharon,

What's wrong with using Start and Finish fields?  By default those will be the early dates or the actual dates (if any).