Task Durations Calculated Incorrectly

[Kurt]

I've searched the discussion group and have not found anyone with exactly
this same issue.

If I create an new task and assign a duration of 1 mon, Project calculates a
duration in excess of that (e.g. Start = 8/1 Calculated Finish = 9/12). The
same is true for any number of months (e.g. 2 month duration, start = 8/1,
calculated finish = 10/27). I have no resources are assigned, no
contigencies, and I have checked the calendar and work time, and nothing
seems incorrect. Also, the calcuated durations for days and weeks appear to
be correct (hence, I've been using those instead of months). I have a work
around but my inability to solve this issue is driving me nuts. Any
assistance it greatly appreciated.

 

[John]

I've searched the discussion group and have not found anyone with exactly
this same issue.

If I create an new task and assign a duration of 1 mon, Project calculates a
duration in excess of that (e.g. Start = 8/1 Calculated Finish = 9/12). The
same is true for any number of months (e.g. 2 month duration, start = 8/1,
calculated finish = 10/27). I have no resources are assigned, no
contigencies, and I have checked the calendar and work time, and nothing
seems incorrect. Also, the calcuated durations for days and weeks appear to
be correct (hence, I've been using those instead of months). I have a work
around but my inability to solve this issue is driving me nuts. Any
assistance it greatly appreciated.

Kurt,
Project calculates duration values in working time, not calendar time.
That's why the default setting under Tools/Options/Calendar is 20 days
per month. Obviously some months have a few more working days.

My guess is that you set the days per month value to be 31. That will
never be true for any month because as I said, Project calculates
duration in working days.

Since there is disparity in the number of working days per month, using
duration values in months is an approximation at best. You are much
better off using duration values of hours, days or weeks since those are
consistent regardless of the month.

If you want duration in calendar days, you will need to enter values in
elapsed time. For example one week is 7ed or 1ew. You could enter
elapsed time for a month (e.g. 1emon) but Project defaults to 31
calendar days for all months (go figure).

Hope this helps.
John
Project MVP

 

[salgud]

I've searched the discussion group and have not found anyone with exactly
this same issue.

If I create an new task and assign a duration of 1 mon, Project calculates a
duration in excess of that (e.g. Start = 8/1 Calculated Finish = 9/12). The
same is true for any number of months (e.g. 2 month duration, start = 8/1,
calculated finish = 10/27). I have no resources are assigned, no
contigencies, and I have checked the calendar and work time, and nothing
seems incorrect. Also, the calcuated durations for days and weeks appear to
be correct (hence, I've been using those instead of months). I have a work
around but my inability to solve this issue is driving me nuts. Any
assistance it greatly appreciated.

I agree with all that John said and add that it's not good scheduling
practice to schedule tasks with a duration of 20 working days. Most would
recommend a maximum of 10 days. Some would even break them up more. The
reasoning is that if something goes wrong in the execution of that one
month (20 day) task, and someone doesn't voluntarily tell the PM
(occasionally, resources have been known to cover up lack of progress),
your project can easily be 20 days behind schedule right from the gitgo.
Not good.

So with longer efforts, it's recommended that you break them up into
smaller tasks for the schedule to avoid this all to common pitfuall.

Hope this helps in your world.

 

[John]

I agree with all that John said and add that it's not good scheduling
practice to schedule tasks with a duration of 20 working days. Most would
recommend a maximum of 10 days. Some would even break them up more. The
reasoning is that if something goes wrong in the execution of that one
month (20 day) task, and someone doesn't voluntarily tell the PM
(occasionally, resources have been known to cover up lack of progress),
your project can easily be 20 days behind schedule right from the gitgo.
Not good.

So with longer efforts, it's recommended that you break them up into
smaller tasks for the schedule to avoid this all to common pitfuall.

Hope this helps in your world.

salgud,
Something go wrong? You can't be serious. Not inform the PM about lack
in progress? Never happen.

It sounds like you need some more discipline in your work environment ;-)

John

 

[salgud]

salgud,
Something go wrong? You can't be serious. Not inform the PM about lack
in progress? Never happen.

It sounds like you need some more discipline in your work environment ;-)

John

Of course, I was referring to extremely rare cases which happened to other
PMs. Never could happen to me!