Task whole v. fraction days

[SarahBelle]

In the under the duration column the days somehow will total to XXX.88 or
XXX.13 days. How do I get rid of the fractional days? (Note: I have made
sure that each of the sub-task days are whole days.)

 

[Gérard Ducouret]

Sarah,

Have a look at the FAQ # 5 : Default working hours,
http://project.mvps.org/faqs.htm#Default Working Hours

Hope this helps,

Gérard Ducouret

 

[SarahBelle]

Thanks.... I can't change the working hours though, can I? I mean, I don't
actually want the time to change, I just want a whole number duration. All
the sub-tasks are in whole numbers, but the main tasks show up with decimals.

 

[Dave]

Thanks.... I can't change the working hours though, can I? I mean, I don't
actually want the time to change, I just want a whole number duration. All
the sub-tasks are in whole numbers, but the main tasks show up with decimals.

Summary tasks are calculated. Therefore the fractional days you are
seeing must be the result of overlap between the associated subtasks.
However as a calculated field the values it contains are right. You
could move the subtasks around so that they only overlap by integral
multiples of days but it seems a bit pointless.

Anyway, why do you care? There is no reason why a project shouldn't
last 81.72 days. It is actually extremely unlikely that it lasts an
exact integral multiple of days.

 

[SarahBelle]

You wrote:
"Anyway, why do you care? "

Seriously? I'm pretty sure it doesn't matter *why* I care. This is a place
to ask questions. I had a question... so I asked it.

At any rate, we fixed the problem and thank you very much to Gerard who
actually pointed me in the direction to see that, if I changed my display to
show the hours, I saw that there were different start times. Making them all
the same got rid of my "extra" days (decimals.)

So, thank you

 

[Steve House]

You really can't guarantee that all durations will work out to whole
numbers, Project stores and calculates durations in minutes to the nearest
10th. A task that is 480 minutes long is only an nice, tidy integer day in
length if the workday is exactly 8 hours long. Couple that with the fact
that a duration is measured in calendar working time units from the moment
work begins until the moment work ends. Now consider a summary task with
two children, each 1 day in length. The first task starts Monday at 8am,
the second starts Monday at 1pm. So the first ends Mon at 5 and the second
Tues at noon. The duration of the summary is 1.5 days and that's
inescapable becuase there are 1.5 working days between Monday 8am (the start
of the earliest to start) and Tuesday at noon (the finish of the last to
finish). I'm sure what you're seeing is some variation of this theme and it
shouldn't worry you, Project is describing physical reality for you.

 

[Steve House]

Sarah, please don't be offended. It matters why you care only because some
issues people raise sometimes point to fundamental misunderstandings with
the way scheduling works. For example, people sometimes think that entering
a duration in days or weeks or months means that Project uses days, weeks,
or months as the time units for its calculations. It does not. Sometimes
best solution to a problem is to change the expectations that created the
problem, especially when the problem is created by the application of
"policy" rather than a reflection of physical reality. I can appreciate
that the boss might be insisting that durations always be integer days but
the best solution is not to fudge the plan to make it appear the way he
wants it, the best solution to the problem is to educate the boss as to why
his expectations doesn't make sense.

 

[Dave]

You wrote:
"Anyway, why do you care? "

Seriously? I'm pretty sure it doesn't matter *why* I care. This is a place
to ask questions. I had a question... so I asked it.

At any rate, we fixed the problem and thank you very much to Gerard who
actually pointed me in the direction to see that, if I changed my display to
show the hours, I saw that there were different start times. Making them all
the same got rid of my "extra" days (decimals.)

So, thank you

You did and you got a good answer to your question (several as it turns
out). The question I asked was to try and understand the true nature of
the problem and why it was important that your schedule showed integral
durations - was it for your understanding of how the application works
or because of some decree by yourself, your boss or your clients or
simple expectation.

I now have another question though. Given that you 'resolved' this by
changing the start times, are you entering start dates for your tasks?
This would widely be regarded as a bad practice as it sets constraints
which may limit the flexibility of Project's calculations. In fact
setting times sets constraints so I would suggest that it would be
better if you didn't do this and let Project calculate the start dates
and times for you as that is what it is intended for (provided that the
plan is loaded with resources). If you do this, you may find that
Project gives non-integral durations for summary tasks, hence my
original question.

Hope this helps.