Updating the schedule in P3

Member for

16 years

Thanks Rafael and Shahul for your inputs. When I said that my understanding was that the schedule is mainly used for dates and not progress, I meant that there’s no need to update the %Comp field in P3; you just need to update Actual Start/Finish and/or Remaining Duration. Physical progress is updated separately, usually in an Excel spreadsheet. I think Rafael is right when he says that the schedule is also used for resource planning.

Member for

21 years 8 months

Shahul,



Scheduling is used for planning not only your dates but also your resources.



Seems like Fernando is starting with the logical thing first, time. When CPM started in the 50’s it was just abouut time, then more functionality was added and still today many don’t realize how they are related. I have clients who do not resource load their jobs, unbelievable but true. How can you make a job without accounting for resources?



Eventually Fernando will get into the other things,very soon, the same way we are frequently helped by others, those of us willing to assit him will be here, Planning Planet is a two way street.



Best regards,

Rafael


Member for

16 years 11 months

Rafel i am unclear with the statement by Fernando

Scheduling is used only for dates?

Member for

21 years 8 months

Fernando:



The very basic updating procedure is to update Actual Start, Actual Finish and %complete/(or remaining duration). I recommend use Actual Start/Actual Finish/Remaining Duration.



For all started but unfinished activities during the update period make sure you have the appropriate remaining duration as it will not necessarily be adjusted automatically.



Remaining duration is measured from Data Date unless you have out-of-sequence progress selected Retained Logic for out-of-sequence progress instead of Progress Override. The selection is an issue per-se for a long debate.



For reasons beyond my comprehension the default set by primavera for %complete and remaining duration is that these are linked, that is one is the function of the other, but this is not always the case, to me keeping them linked does not make sense. Therefore you got to go to the options screen and make the appropriate selection.



You can enter the data from several screens, is your choice. You can also use Primavera Mail utility to make your updates but again for reasons beyond my comprehension the default setting by primavera is to update using %complete.



Also %complete is used to update other fields depending on your settings. Because I no longer use P3 and do not have a license installed in my computer I cannot tell you specifically which options you have.



If your job is resource and cost loaded, then as part of your regular updating you have to update actuals for resource usage and costs. With regard to costs in order to get true time/cost distributions you got to follow a procedure to update actuals, is irreversible in P3. Here P3 is the worst of all software.



Best regards,

Rafael

Member for

16 years

Thanks Rafael for your answer. My understanding is that the schedule is used for DATES, not for PROGRESS (you plan and control the time of your project, i.e. from the schedule you are able to know your mechanical completion date).



Having said that, I have two more questions:



1. Shouldn’t you just update your Actual Date and / or Remanind Duration fields / columns everytime you update your schedule (i.e. on a bi-weekly basis)?



2. Why do you need to update the %Comp (percentage) field / column in P3 if your progress report is being done separately in Excel? Or, do you use the %Comp field / column in P3 for physical progress reporting purposes?

Member for

21 years 8 months

Fernando,



If you have linked %complete and remaining duration then whenever you edit one the other is recomputed according to the following formulas.



If you enter %complete remaining duration will be recomputed as follows:

REMAINING = ORIGINAL (1 - %COMPLETE) when there is no actual, otherwise

REMAINING = (ACTUAL/%COMPLETE) – ACTUAL



If you enter remaining duration %complete will be recomputed as follows:

%COMPLETE = 1 – REMAINING/ORIGINAL when there is no actual, otherwise

%COMPLETE = ACTUAL / (ACTUAL + REMAINING)



This method might create confusion, especially after you have actuals from previous updates. Let say you have an activity with original duration of 2 weeks but after 2 weeks is 50% done and you expect to finish the remaining 50% in one week for a total duration of 3 weeks. If you enter these values into the above formulas you will get:

REMAINING = 2 /.5 – 2 = 4 – 2 = 2 weeks

%COMPLETE = 2 / (2+1) = 2/3 = 0.667= 66.67%

This mean you should have entered 66.67% to get 1 week for remaining duration.

REMAINING = 2 / 0.6667 – 2 = 3 – 2 = 1 week



The automatic linking of the two is one of the most common pitfalls of scheduling software programs. Cost loaded schedules are particularly susceptible to this scheduling pitfall, because the percent complete is tied to the earned value and cost to complete for each activity. Thus the percent complete must be accurately reported otherwise the cost reports will be inaccurate.



You have two options:



1.     Keep the formula link and in the activity details enter either and the software will recalculate the other as per your last entry. Here formulas might confuse you.

2.     Unlink the formulas and set each individually. Keep it simple and avoid any pitfall.



My recommendation is go with option 2, and then ask at the site, what is the remaining duration in work days after the update data date. You will enter remaining durations for your activity duration computations and no change in %complete will be done at this point. You will enter %complete for your cost and EV computations and no change in remaining duration will be done at this point.



KEEP THEM SEPARATE.



Best regards,

Rafael

Member for

16 years 11 months

percentage of completion is proportional to progress

you could load weight age resource and keep updating it as you mentioned in brackets

Member for

16 years

Hi Shahul, thanks for your answer. Now, does this % Comp (percentage) field have to do anything with the progress you do separately? (i.e. in construction each activity is typically given a weighting based on manpower or cost, and percentage complete is physically measured / estimated on site).

Member for

16 years 11 months

1. you need to plug in actual dates,percentage in activity column and press f9



2.If you use tools update progress you don’t have to plug in anything since it is used to show planned percentage



3.changes to data should be done before scheduling



4.Data date shifts according to scheduling dates u mention in the scheduling option