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Resource driving dates with zero remaing effort

12 replies [Last post]
Andrew Dick
User offline. Last seen 8 years 10 weeks ago. Offline
Joined: 14 Feb 2007
Posts: 295
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. I’m 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

Replies

Andrew Dick
User offline. Last seen 8 years 10 weeks ago. Offline
Joined: 14 Feb 2007
Posts: 295
David,
Some answers below;

1) Nature of resources in your plan. Are they "pools of trade" e.g. I have 10 riggers, 12 scaffolders etc, OR named individuals, e.g. Fred Smith, Mechanical engineer. A = (Both), we’re using pools/parent resources for forward planning and named resources for timesheets (when we get told who is actually on the job)

2) Is timesheet data used to update actual hours. A = unfortunatley yes

3) If you asked an engineer "how big is that job" would they say:

Its a 3 day job A = Engineer 1
Its a 4 man job A = Engineer 2
Its a 50 manhour job A = Engineer 3

- and then PM/PD says Bu!!Sh!t and tells us what they want

4) Are you "client" or "contractor" A = Middle man

5) Is measuring growth important A = In scope YES!!!!

6) do you use just the P5/6 Windows client only, or some of the web stuff A = Client only at this time (Version 5 SP4)


So there you have it, and I had further confirmation today from a Primavera Rep that if I wish to avoid my original issue with the resource that is on holidays with no remaining effort - still driving the end date of the activity out, I will need to manage at the individual assignments level.

Ya! for me ;-)
David Kelly
User offline. Last seen 1 year 34 weeks ago. Offline
Joined: 19 Oct 2004
Posts: 630
Andrew,

Some questions. They help me setup the parameters.

1) Nature of resources in your plan. Are they "pools of trade" e.g. I have 10 riggers, 12 scaffolders etc, OR named individuals, e.g. Fred Smith, Mechanical engineer.

2) Is timesheet data used to update actual hours.

3) If you asked an engineer "how big is that job" would they say:

Its a 3 day job
Its a 4 man job
Its a 50 manhour job

4) Are you "client" or "contractor"

5) Is measuring growth important

6) do you use just the P5/6 Windows client only, or some of the web stuff



Alex Wong
User offline. Last seen 11 years 6 days ago. Offline
Joined: 12 Feb 2003
Posts: 874
Groups: TILOS
In addition,

I have seen too often that activity marked with Zero remaining duration and without a actual finish date or 100% completed without actual finish date.

When you schedule project that contain these condition it (the system) gives you a warning and ask to rectify the problem, but again once too often, planner just ignore these warnings.

As a planner, our value is to base on current progress and information and predict the outcome of the project... in terms of time, and maybe cost as well. So accurate information is need to have a right prediction or simulation. Shxx in Shxx out


Alex
Alex Wong
User offline. Last seen 11 years 6 days ago. Offline
Joined: 12 Feb 2003
Posts: 874
Groups: TILOS
Hi Andrew

I can only guess why Primavera design it in such a way that you can have individual resource can allocate different period of time within the activity period.

In the past, both MSP and P3 do not allow this so that the resource is always spread across the duration, as a result, if you have a resource only required during the begining or end of the activity will require an additional activity seperate due to the constraint. And within a complex network, more activity means more daily maintainence. As a result, in P5, each resource assignment is independent with its own Start and Finish date. In addition, you can still setup the activity without assign individual start and finish date, the system will generate base on the activity dates.

Because of that it gives the flexibility for planner to either update @ activity level or resource level.

The planner have to decide which level he/she require to be updated. All these is pave the way to use timesheet in the system so that individual resource can still assign their completion date for part of the works required for the activity without update the activity as completed.

HTH,

Alex
Andrew Dick
User offline. Last seen 8 years 10 weeks ago. Offline
Joined: 14 Feb 2007
Posts: 295
Alex,
I agree with the first scentence of your second paragraph, as far as setting the activity type to task dependant, this would defeat the initial purpose of identifying schedule delays attributed to resources being on leave (using their own calendars to plan that).

The issue is the fact that Primavera requires you to manage each resource assignment on an individual basis and track the finish date of each assignment and subsequently update the assignment if the work has been completed.

This to me seems over cumbersome, and quite silly that you must manage down to such a low level within your programs just to get the software to tell you when an activity will potentially finish.

I also agree that there are a great number of settings (bells & whistles) that are availible to the user as a whole, and this proves to be the bain of my existance in trying to figure out which ones are the best to use when even Primavera themselves can’t seem to tell me.

Andy
Alex Wong
User offline. Last seen 11 years 6 days ago. Offline
Joined: 12 Feb 2003
Posts: 874
Groups: TILOS
Hi Andrew,

Just reading the original question, It seem that the activity you setup is contradict with the progress data.

If you set up the activity as Resource Dependent then when the resource is finished (no remaining unit) then it should be finished as well. And since the activity is not yet finish and you should change the activity type as task dependent.

As of course there are number of different setting combination in Primavera. However, as a planner, we should setup the appropriate setting for a specific type of activity.

Good Luck.

Alex
Andrew Dick
User offline. Last seen 8 years 10 weeks ago. Offline
Joined: 14 Feb 2007
Posts: 295
David,
Thanks for your comments, however I’m very surprised that someone has worked out the best settings for anything, given the number of combinations you can have.

The reason for my selections are purely based on Primavera suggestions to my predecessors when the company purchased the tool.

I have been on a quest for the holy grail, so to speak, when it comes to the desired settings.

So if you can knock that book up in the next day or so I’m sure there would be just more than me who would buy a copy.

Anyway, I did try the resource dependant activities as you suggest and soon turned those back to task dependant. I’d love to have enough hard eveidence tobuild a case to turn of the "drive activity dates by default" . So I would be appreciative of any direction you may provide me there.

Thanks
Andy
David Kelly
User offline. Last seen 1 year 34 weeks ago. Offline
Joined: 19 Oct 2004
Posts: 630
Andrew,

VERY surprised that someone with "construction" in their job title/industry is using "drive activity dates by default" as a project level setting. I’ve always found that to be a ticket to the madhouse.

Next you will tell me you are using "resource dependant" activities! (I reckon on 50mg Valium for each resource dependant activity in a construction schedule)

I guess 50% of my time as Primavera Consultant/Trainer/Representative is talking to clients about these settings.

Maybe I should write the book, I certainly talk it nearly every day.

But just to be serious for a minute... The settings I see described in the text of the emails between yourself and Primavera seem ideal for a software development project - so "Railway Construction" seems to fit quite badly with that.



Andrew Dick
User offline. Last seen 8 years 10 weeks ago. Offline
Joined: 14 Feb 2007
Posts: 295
Fair enough,
I think that oneday someone will finally work out which combination of the bells and whistle selections works best.

For now Primavera have told me that to overcome this issue, you need to do on of 2 things;

Apply an actual finish date to each resource assignment on each activity as soon as they are finished the work they need to do on the activity.

And, deselect the Resource Dirve Activity Dates.

It seems that the scheduler will still take into account the resource availability in predicting the end date of the activity even if there are no hours left in their remaining.

Andy
Anoon Iimos
User offline. Last seen 2 years 10 weeks ago. Offline
Joined: 22 Sep 2006
Posts: 1422
Andrew,

Sorry I cannot, i’m also lost in this matter and wondering why there are too many options. It is that I just prefer to use Fixed Units as it will be derived from your given quantities (i.e. from BOQ). When making schedules, I prefer that Durations and Resources are flexible as these are the variables which means changeable and impossible to be fixed unless you forced it. While the Units can only be changed upon approval of something (i.e. Change Order or Variations).

??? have I got a point? really I don’t know!
Andrew Dick
User offline. Last seen 8 years 10 weeks ago. Offline
Joined: 14 Feb 2007
Posts: 295
Anoon,
Thanks for that, but could you explain a bit more?

Andy
Anoon Iimos
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Joined: 22 Sep 2006
Posts: 1422
Unsolicited Comment:

Regarding Settings:

Scheduling settings
Progress override selected
No other tick boxes selected

Activity settings
Type = Resource Dependant
Duration type = Fixed units time
% Complete = Duration

I just thought that the above settings are conflicting, i.e. Fixed units time and Resource Dependent; % Complete Calculation which was set on Duration against Resource Dependency...