Ok Planners,
Lets see if we can discount my theory and opinions.
The text below is from a request that I logged into the POINT site for Primavera regarding some funny happenings that I found in one of our schedules a few weeks ago.
The way I nderstand the response, what I found is completley normal behaviour for Primavera.
In the past the tools that I have used have worked somewhat differently, in that if the resource had no remaining effort,then that resource was not taken into account for the EF date of the activity.
Anyway if some of those more committed folk can have a read of the text below and provide me some different feedback that would be great.
Also if I’m way off base and have done something silly and missed one of the beel & whistle selections in Primavera please feel free to scold me on that.
Enjoy
Andy
P.S. Im using P5 SP3
- Customer Question
Please clarify the following situation for us;
Project Settings
Active
Checked in
Not levelling
Drive activity dates by default (ticked)
Scheduling settings
Progress override selected
No other tick boxes selected
Activity settings
Type = Resource Dependant
Duration type = Fixed units time
% Complete = Duration
Resource Assignment details (for the resource in question)
Remaining Units/Time 8H/d
Budgeted units 4
Actual units 2
Remaining units 0
At complete units 2
Original lag 0
Resource in question is not the primary resource.
Resource Settings
Default Units/Time 8H/d
Max Units/Time 8H/d
Calender = Resource specific with holidays (Linked to ops group global calendar)
Resource ‘Indie Lail’ is delaying the end of the activity to be equivalent with his return to work as dictated by his individual resource calendar (08OCT07)
If holidays are removed the activity finishes 10SEP07
If drive activity dates by default is deselected at the resource assignment the activity finishes on the 10SEP07
Question – Why when a resource has zero remaining units does the scheduling engine delay the finish of the activity to accommodate that resource being on holidays ( the other resource is also set at driving and is available)
Please advise
Thanks
Andy
- Primavera Response
Hello Andy,
I am assuming that holidays for the resource are occupying over a period from Oct 8th - Sept 9th. The reason that I am assuming this is that an activity cannot be schedule to finish until there is valid work time on the calendar (in this case the resource calendar as it is a resource dependent activity). I would however, need more data on this issue to give you an exact cause. Can you send in a copy of the project in XER format?
Thank you.
- Primavera response
Hello Andrew,
Do you still have questions on this issue? I have not heard back from you since my last response. Please let me know if there is anything that I can assist you with. Thank you.
Sincerely,
- Customer response
Yes the problem still exists.
Your initial response was somewhat confusing; as I previously described the details surrounding the resource assignment as having ZERO (0) remaining hours to perform on the activity, therefore the other resource should have been able to execute their hours without impact from the resource on holidays.
The fact was that the activity finish date scheduled to the end of the holidays for the initial resource.
So the question is, Why when a resource has no effort to perform on an activity do the Early Dates, (Time analysis only??? if that’s how Primavera actually works), move to accommodate the resource on holiday.
This is completely and utterly illogical and makes no sense at all.
I have attached an XER of the project in question.
The activity ID is 409229040 and the resource in question is Indie Lail.
Thanks
Andy
- Primavera Response
Hello Andy,
I am having a tough time duplicating what you are seeing. I have removed the holidays from Indie Lail’s calendar and seen no change. I have also unchecked the option to drive activity dates and seen no change.
What holidays and from what calendar did you remove the days from?
If you would like, you could send in a copy of the DB so that I can look at your exact data rather than dealing with an import.
Thank you.
- Customer response
The holidays were documented in and removed from the resource calendar which is linked to the global calendar.
As for the database, it wouldn’t be very easy to do this.
Andy
- Primavera Response
Hello Andrew,
I think we are getting closer to a resolution for you issue. I think the copy of the schedule you have sent me has been updated to a different point in time. The data date of the schedule that you have sent me is October 6th 2007, I am unable to duplicate the same behaviour that you are seeing in this specific copy. I noticed in your screenshots, the data date is set back to some time in early September, I am assuming prior to September 10th, hence the results that you are seeing. Therefore, if that is the case, my original explanation is correct.
If the data date was September 1st or later, the resource could not finish earlier than the data (even though there are no remaining units). Hence, an actual finish should have been applied earlier than September 1st. So since the resource does not have work time (even though there are no remaining units), the schedule has computed that the next available time the resource can finish is on the next available work time which is October 8th (as non work time extends from Sept 1st - Oct 5th and Oct 5th is a Friday, so the next work time is the 8th of Oct, a Monday). This is why the resource is being delayed. It appears someone forgot to assign an actual finish on this resource prior to the previous data date.
Sorry for the delay on this issue, however, I just realized the copy that was sent was not status up to the same point. Please let me know if you have any questions. Thank you.
- Customer response
The data date was earlier than the early finish of the activity, using the resource calendar with holidays just blew the date out more. Also the schedule end date was affected.
If we are to use software to predict the end date of an activity, we need it to do it right. This proposed idea that you have submitted is flawed.
If the resource has no remaining effort then he/she should be completely ignored by the algorithm, even WORSE the activity end date blew out all by itself, in other words I was purely looking to see the early finish of the activity.
Even if we take into account the following definitions;
Early dates - calculated in the forward pass of time analysis, early dates are the earliest dates on which an activity can start and finish.
Early Finish Date (EF) - In the critical path method, the earliest possible point in time on which the uncompleted portions of an activity (or the project) can finish based on the network logic and any schedule constraints. Early finish dates can change as the project progresses and changes are made to the project plan.
The idea of the software even considering the resource that is on holidays is laughable.
I will admit that there may even be a setting that I have not got quite right, a radio button not selected, but I hoped that you could tell me this.
If indeed there are no settings I have missed, then, I stand by my opinion that the software is flawed.
Sorry but I have used tools that do this properly in the past.
- Primavera Response
Hello Andrew,
The bottom line on this issue is that you have the option ’drive activity dates’ selected at the resource level. Since the next available work time on the resource calendar (ahead of the data date) is when the resource resumes, this is where the activity finish is scheduled to.
This is the same principle as early dates, if the activity calendar did not have valid work time unit Oct 8th 2007, then the earliest calculated finish would be Oct 8th as well (that is if the activity was task dependent). When the task is resource dependent the resource calendar is used and when you check the option to ’drive activity dates’ that means the resource is driving the dates of the activity. If you don’t apply an actual finish to the resource or activity, the scheduler will continue to schedule the early finish on the next available work time according to the calendar specified by the task type, which in your case if after the resource vacation time.
I am not sure how much deeper we can get into the issue. I could create an enhancement request for this issue. If you would like me to do that, would you be able to provide me with a description of the enhancement and how you would like it to work within the application?
Thank you.
- Customer Response
It seems that your second paragraph is suggesting that the individual resource assignment can be closed/finished by applying an actual finish to the resource, I take it from this that if this were to occur, the resource would no longer be used in the calculations for the activity EF date?
Can you imagine the effort required on any project schedule where the planner has to go and close off all of the completed resource assignments on individual activities, I could probably just use a global change, but you would still need to establish the status of the activity to ensure that the resource really is finished all the work and not just over budget.
This being the case, I would like to send you some details for an enhancement request. I still feel that if the resource has zero remaining units on the activity then that resource should NOT be used in any equation to predict the early finish of the activity. This could be accomplished far more easily by using the calculation algorithm. I have some great reservations about the accuracy of any of my schedules now if this is the method of operation of the tool.
Anyway, I’ll document a possible enhancement request and send it through.
Thanks for your feedback on this matter.
Andy
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