If given the option (and sometimes clients do not give me the option for the reasons you outline), I would always choose to manually enter RD.
As you say, you should get a more realistic schedule with this method, particularly if your schedule contains a high number of non-linear activities where % complete will bear little / no relation to RD (eg design activties).
The downside you mention, that it allows for schedule manipulation, I regard as a releatively minor concern since the primary use of a project schedule should always be as a tool to help the project team manage the project, not as a reporting tool to the client.
I much prefer to follow the method which will provide the greater schedule accuracy, which should therefore give me the greater chance of making the right decisions at the right time to help the project be delivered on time and on budget.
If to do this I have to accept a slightly higher risk of being lied to during project updates then so be it. -Part of my job as a client planner is to spot these lies anyway.
Short answer:
The schedule exisits as a project control tool, not a project reporting tool.
manually updating RD makes the schedule more accurate and hence a better project control tool than using % complete to calculate.
One might set % complete type of an activity as 'physical' and enter RD manually during update process or allow primavera to calculate RD based on OD and Activity % Complete if the % complete type is 'duration'. Both options have plusses and minuses. In the first case, you might have a more realistic schedule because you track the main driver of scheduling dynamically and irrespective of % Complete. On the other hand, it allows the user to manipulate the schedule to recover disruption. In the second option, RD depends on your initial/approved estimate and progress of the activity. Once you calculate the % complete, RD updates itself as a proportion of OD and cannot be misused but it might not reflect the current status properly.
In this context, could you please give your further opinion about the methods of revising RD? Which option governs? Any suggestions?
Best regards,
Baris
Member for
21 years 7 months
Member for21 years8 months
Submitted by Rafael Davila on Sat, 2011-08-06 20:27
In the old days prior to the PC most people were supplied with a Bar Chart frozen in time and updating was done by shading the fixed bars to represent the % done. The DD or data date was represented with a red line or a red string you would be moving from period to period. The difference from end of shade to DD on unfinished activities represent how much ahead or behind progress is from the frozen schedule.
This was ok for Bar Charts but is not the appropriate for a CPM schedule.
If this is what you want to do, it can be done. Use a baseline you will update your percentages without executing a schedule run that will change the dates. Use another schedule to represent current equal to the baseline but that will display only the baseline bars, no current baseline bars but updated to DD. This presentation will display fixed in time bars and current DD. If you want to display true current bars you can also do it.
Member for
16 years 7 months
Member for16 years7 months
Submitted by Gary Whitehead on Sat, 2011-08-06 12:33
From your question, I'm guessing you are used to using Microsoft Project, and don't really understand the concept of a data date? Read up on data dates in the help files, becuase it is a fundamental difference between how Primavera and MSP work.
For activities that have started but not been completed, Primavera calculates the (Early) finish date as Data date + Remaining Duration. Remaining Duration can either be entered manually, or Primavera will calculate that for you based on the % complete you give it.
So when you give it a later data date without reducing the remaining duration or increasing the % complete, Primavera assumes no progress has been made in the period between the two data dates and and such pushes the finish date out.
3 ways to avoid this:
1) (Best practise) -Review/Revise your remaining duration for every in progress activity each time you change the data date
2) (Poor Practise) -Select the "Use Expected Finish Date" option you found, and make sure you enter the right date in the "exp finish" box for each activity. This will tell Primavera to use this exp finish instead of calculating the finish date, until/unless this finish date is earlier than the new data date
3) (Worst practise) -Use progress spotlight and update progress options to tell Primaver to assume all activities have made precisecly as much progress as was planned when scheduleing to a new data date
For activities that have not started, Primavera will not allow a start date earlier than the data date (which would be impossible), so will push any offending activities back so the start date equals the 1st working day from data date onwards.
Member for
16 years 7 monthsBaris, Long answer: If
Baris,
Long answer:
If given the option (and sometimes clients do not give me the option for the reasons you outline), I would always choose to manually enter RD.
As you say, you should get a more realistic schedule with this method, particularly if your schedule contains a high number of non-linear activities where % complete will bear little / no relation to RD (eg design activties).
The downside you mention, that it allows for schedule manipulation, I regard as a releatively minor concern since the primary use of a project schedule should always be as a tool to help the project team manage the project, not as a reporting tool to the client.
I much prefer to follow the method which will provide the greater schedule accuracy, which should therefore give me the greater chance of making the right decisions at the right time to help the project be delivered on time and on budget.
If to do this I have to accept a slightly higher risk of being lied to during project updates then so be it. -Part of my job as a client planner is to spot these lies anyway.
Short answer:
The schedule exisits as a project control tool, not a project reporting tool.
manually updating RD makes the schedule more accurate and hence a better project control tool than using % complete to calculate.
Cheers,
G
Member for
15 years 10 monthsMr. Whitehead,One might set
Mr. Whitehead,
One might set % complete type of an activity as 'physical' and enter RD manually during update process or allow primavera to calculate RD based on OD and Activity % Complete if the % complete type is 'duration'. Both options have plusses and minuses. In the first case, you might have a more realistic schedule because you track the main driver of scheduling dynamically and irrespective of % Complete. On the other hand, it allows the user to manipulate the schedule to recover disruption. In the second option, RD depends on your initial/approved estimate and progress of the activity. Once you calculate the % complete, RD updates itself as a proportion of OD and cannot be misused but it might not reflect the current status properly.
In this context, could you please give your further opinion about the methods of revising RD? Which option governs? Any suggestions?
Best regards,
Baris
Member for
21 years 7 monthsIn the old days prior to the
In the old days prior to the PC most people were supplied with a Bar Chart frozen in time and updating was done by shading the fixed bars to represent the % done. The DD or data date was represented with a red line or a red string you would be moving from period to period. The difference from end of shade to DD on unfinished activities represent how much ahead or behind progress is from the frozen schedule.
This was ok for Bar Charts but is not the appropriate for a CPM schedule.
If this is what you want to do, it can be done. Use a baseline you will update your percentages without executing a schedule run that will change the dates. Use another schedule to represent current equal to the baseline but that will display only the baseline bars, no current baseline bars but updated to DD. This presentation will display fixed in time bars and current DD. If you want to display true current bars you can also do it.
Member for
16 years 7 monthsFrom your question, I'm
From your question, I'm guessing you are used to using Microsoft Project, and don't really understand the concept of a data date? Read up on data dates in the help files, becuase it is a fundamental difference between how Primavera and MSP work.
For activities that have started but not been completed, Primavera calculates the (Early) finish date as Data date + Remaining Duration. Remaining Duration can either be entered manually, or Primavera will calculate that for you based on the % complete you give it.
So when you give it a later data date without reducing the remaining duration or increasing the % complete, Primavera assumes no progress has been made in the period between the two data dates and and such pushes the finish date out.
3 ways to avoid this:
1) (Best practise) -Review/Revise your remaining duration for every in progress activity each time you change the data date
2) (Poor Practise) -Select the "Use Expected Finish Date" option you found, and make sure you enter the right date in the "exp finish" box for each activity. This will tell Primavera to use this exp finish instead of calculating the finish date, until/unless this finish date is earlier than the new data date
3) (Worst practise) -Use progress spotlight and update progress options to tell Primaver to assume all activities have made precisecly as much progress as was planned when scheduleing to a new data date
For activities that have not started, Primavera will not allow a start date earlier than the data date (which would be impossible), so will push any offending activities back so the start date equals the 1st working day from data date onwards.
Cheers,
G