Summary Task Percent Complete Incorrect

[mikejw]

Hello,

I have several groupings that have a summary task and 10 milestones (0
duration) underneath. At the moment, 8 of those milestones have been
completed, 2 are incomplete, however, the percent complete on their summary
task is showing 0%. Playing around, I noticed that if I change the duration
from 0 to 1, the corrrect percent complete shows up at the summary level.

Can someone help me understand why the summary task's percent complete is
not being updated as task below it complete?

Thank you,

MikeW

[Trevor Rabey]

Everyone who has ever used MSP notices this and the question pops up in the
group at frequent, regular intervals.
Then everyone tries to explain about how milestones are just "punctuation",
not real tasks, so progress of nothing is nothing, and overall progress of a
bunch of nothings is nothing.
Also, the Summary progress calculation does the best it can but there are so
many different ways to combine, link and overlap tasks and milestones under
a Summary, and so many ways that they can all be not started, in progress or
finished, that no one is ever really happy that Summary progress looks
right.
It's an average of the % Complete of what's done, or something like that but
so what? I don't even remember the exact algorithm without testing and
checking examples. Someone will.

My point is, it's irrelevant, and there is no point in puzzling over it
because Summary % Complete has no useful meaning, no matter how it is
arrived at.
It is certainly no indicator of anything connected with progress or
performance, and it does not provide any clue about what should be done.
--
Trevor Rabey
0407213955
61 8 92727485
PERFECT PROJECT PLANNING
www.perfectproject.com.au

Post by mikejw
Hello,
I have several groupings that have a summary task and 10 milestones (0
duration) underneath. At the moment, 8 of those milestones have been
completed, 2 are incomplete, however, the percent complete on their summary
task is showing 0%. Playing around, I noticed that if I change the duration
from 0 to 1, the corrrect percent complete shows up at the summary level.
Can someone help me understand why the summary task's percent complete is
not being updated as task below it complete?
Thank you,
MikeW

[Jonathan Sofer [MVP]]

% Complete is based on duration so that makes sense. It can't determine the
% complete unless all the milestones are complete at which point the summary
will show 100%.

Jonathan

Post by mikejw
Hello,
I have several groupings that have a summary task and 10 milestones (0
duration) underneath. At the moment, 8 of those milestones have been
completed, 2 are incomplete, however, the percent complete on their summary
task is showing 0%. Playing around, I noticed that if I change the duration
from 0 to 1, the corrrect percent complete shows up at the summary level.
Can someone help me understand why the summary task's percent complete is
not being updated as task below it complete?
Thank you,
MikeW

[vanita]

Hi MikeW

% complete is based on duration and is connected with the data in the two
columns of 'Actual Duration' and 'Remaining duration'. For milestones these
data are 0 so consolidated % complete for Summary tasks would also be 0.

If for each milestone completion you want to show 10% complete, i.e with 8
milestones complete, Summary task should show 80% complete you may insert a
Text column e.g Text1 and for Summary tasks you may yourself input data
accordingly in that column. You may also customise the Gantt area to show
Text1 data alongwith the bars.

I hope it helps.
Vanita
--
Project Management consultant and trainer

Post by mikejw
Hello,
I have several groupings that have a summary task and 10 milestones (0
duration) underneath. At the moment, 8 of those milestones have been
completed, 2 are incomplete, however, the percent complete on their summary
task is showing 0%. Playing around, I noticed that if I change the duration
from 0 to 1, the corrrect percent complete shows up at the summary level.
Can someone help me understand why the summary task's percent complete is
not being updated as task below it complete?
Thank you,
MikeW

[Jim Aksel]

This behavior is by design. If the subtasks under a summary task are all
milestones (0 duration) then summary %Complete remains at 0% until all
subtask milestones are completed. This is to avoid a division by 0 problem.

Although I do not specifically cover this case, if you read my white paper
on my blog you will see how %Complete is calculated (it is weighted by
duration). In your case, the sum of all the durations is still 0 which is
what creates the problem. Should you be so inclined, visit the link below,
select Project Tips and then hunt for the white paper on Percent Complete
which explains how it is calculated.

Strangely enough, 0/0 in mathmatical terms is 1 by definition (or at best is
indeterminate). What you seek is a count of complete milestones divided by
total number of milestones. You would have to do that in two custom number
fields with formulas and then divide the results at the summary level.
--
If this post was helpful, please consider rating it.

Jim Aksel, MVP

Check out my blog for more information:
http://www.msprojectblog.com

Post by mikejw
Hello,
I have several groupings that have a summary task and 10 milestones (0
duration) underneath. At the moment, 8 of those milestones have been
completed, 2 are incomplete, however, the percent complete on their summary
task is showing 0%. Playing around, I noticed that if I change the duration
from 0 to 1, the corrrect percent complete shows up at the summary level.
Can someone help me understand why the summary task's percent complete is
not being updated as task below it complete?
Thank you,
MikeW

[Trevor Rabey]

Jim, there is no chance that 0/0 even exists let alone is equal to 1.
--
Trevor Rabey
0407213955
61 8 92727485
PERFECT PROJECT PLANNING
www.perfectproject.com.au

Post by Jim Aksel
This behavior is by design. If the subtasks under a summary task are all
milestones (0 duration) then summary %Complete remains at 0% until all
subtask milestones are completed. This is to avoid a division by 0 problem.
Although I do not specifically cover this case, if you read my white paper
on my blog you will see how %Complete is calculated (it is weighted by
duration). In your case, the sum of all the durations is still 0 which is
what creates the problem. Should you be so inclined, visit the link below,
select Project Tips and then hunt for the white paper on Percent Complete
which explains how it is calculated.
Strangely enough, 0/0 in mathmatical terms is 1 by definition (or at best is
indeterminate). What you seek is a count of complete milestones divided by
total number of milestones. You would have to do that in two custom number
fields with formulas and then divide the results at the summary level.
--
If this post was helpful, please consider rating it.
Jim Aksel, MVP
http://www.msprojectblog.com

Post by mikejw
Hello,
I have several groupings that have a summary task and 10 milestones (0
duration) underneath. At the moment, 8 of those milestones have been
completed, 2 are incomplete, however, the percent complete on their summary
task is showing 0%. Playing around, I noticed that if I change the duration
from 0 to 1, the corrrect percent complete shows up at the summary level.
Can someone help me understand why the summary task's percent complete is
not being updated as task below it complete?
Thank you,
MikeW

[Jim Aksel]

Yes, it is a strange one. There are two competing math rules at play.

1. Any number divided by itself is 1
2. Any number divided by 0 is infinity.

Since this doesn't make sense, it certainly is indeterminate.

We'll leave it to the math PhDs to reconcile. It will give them something
to do :)

Jim

_______________

Post by Trevor Rabey
Jim, there is no chance that 0/0 even exists let alone is equal to 1.
--
Trevor Rabey
0407213955
61 8 92727485
PERFECT PROJECT PLANNING
www.perfectproject.com.au

Post by Jim Aksel
This behavior is by design. If the subtasks under a summary task are all
milestones (0 duration) then summary %Complete remains at 0% until all
subtask milestones are completed. This is to avoid a division by 0 problem.
Although I do not specifically cover this case, if you read my white paper
on my blog you will see how %Complete is calculated (it is weighted by
duration). In your case, the sum of all the durations is still 0 which is
what creates the problem. Should you be so inclined, visit the link below,
select Project Tips and then hunt for the white paper on Percent Complete
which explains how it is calculated.
Strangely enough, 0/0 in mathmatical terms is 1 by definition (or at best is
indeterminate). What you seek is a count of complete milestones divided by
total number of milestones. You would have to do that in two custom number
fields with formulas and then divide the results at the summary level.
--
If this post was helpful, please consider rating it.
Jim Aksel, MVP
http://www.msprojectblog.com

Post by mikejw
Hello,
I have several groupings that have a summary task and 10 milestones (0
duration) underneath. At the moment, 8 of those milestones have been
completed, 2 are incomplete, however, the percent complete on their summary
task is showing 0%. Playing around, I noticed that if I change the duration
from 0 to 1, the corrrect percent complete shows up at the summary level.
Can someone help me understand why the summary task's percent complete is
not being updated as task below it complete?
Thank you,
MikeW

.

[Steve House]

Adding to the other's comments, a summary task with only milestones as it's
children makes no sense from a schedule standpoint. The project plan is a
detailed model of exactly what ACTIONS have to take place in order to create
the milestones. All you have there is a to-do list. It gives you no
guidance as to what has to happen to achieve your objectives, thus there is
nothing to measure progress towards those objectives against.
--
Steve House
MS Project Trainer & Consultant

Post by mikejw
Hello,
I have several groupings that have a summary task and 10 milestones (0
duration) underneath. At the moment, 8 of those milestones have been
completed, 2 are incomplete, however, the percent complete on their summary
task is showing 0%. Playing around, I noticed that if I change the duration
from 0 to 1, the corrrect percent complete shows up at the summary level.
Can someone help me understand why the summary task's percent complete is
not being updated as task below it complete?
Thank you,
MikeW

[s***@gmail.com]

Post by mikejw
Hello,
I have several groupings that have a summary task and 10 milestones (0
duration) underneath. At the moment, 8 of those milestones have been
completed, 2 are incomplete, however, the percent complete on their summary
task is showing 0%. Playing around, I noticed that if I change the duration
from 0 to 1, the corrrect percent complete shows up at the summary level.
Can someone help me understand why the summary task's percent complete is
not being updated as task below it complete?
Thank you,
MikeW

'% complete' calculation for Detailed Tasks and Summary Tasks are done in different ways.
For a detailed task, the '% complete' is calculated by dividing it's 'Actual Completed Duration' by it's ' Original Duration'
For Summary Task, the '% complete' is calculated by summing up all the 'Actual completed Durations' of all it's sub tasks and then dividing this value by ' Sum of all it's Original Durations'.
Then the Actual Duration for summary task is calculated by multiplying the %complete calculated in the above manner with the Original Duration of the summary task.