13 months in a year??
 

I am trying to set up a plan with units of months over a four year period. When I create a task and give it a duration of 48 mo starting at 'T', it is shown on the Gantt chart as lasting for about 3 years and 9 months, and in the task inspector as having a duration of 191w and 4d. If I manually stretch the task bar until it reaches the 4 year mark, it is shown as having a duration of 52 months!

I guess that I need to do something with the calendar or with the effort conversion factors, but what? Since I am only planning in months, I don't care about the time or length of the working week, or anything like that.

It looks like the settings you want are 174 hours/month and 2088 hours/year in the project effort conversion factors, which it sounds like you've already located in the project inspector.

Thanks - but why?
 

Thank you for these 'magic' numbers. But how did you discover them, and what do they mean?

Perhaps Omni ought to add a section in the 'Help' or FAQ to explain....

365 days/year
5/7 of these days are work days, or 260.7
We'll round up to 261 since we ignored leap years
261 days/year * 8 hours/day is 2088 hours/year
2088 hours/year divided by 12 months/year = 174 hours/month
Obviously, some months have one more work day than others, so that's still approximate.

The default 20 work days/month (160 hours/month) kind of accounts for the fact that there will be national holidays, vacation time, and other days lost.

261 work days/year - 10 vacation days - 8 national holidays* = 243 work days
Throw in 3 sick days, and you get 240 work days/year, or 20 work days/month.

*I counted 2 days each for Christmas and Thanksgiving, 1 each for New Year's, 4th of July, Labor Day and Memorial Day. Obviously, various countries and various businesses observe different holidays.

Micrology,

Let me ask this... if you scheduled a task for the entire calendar month of January and then resource leveling or new dependencies pushed the task back, would you expect it then to take up the calendar month of February? The issue here is that, in 2008 (leap year) it would have to become 2 days shorter. If the answer is yes, I believe what you really want is monthly scheduling granularity. Any task that would normally begin after the first working moment of the month would be automatically pushed to the next month. Task end dates would be automatically pushed out to the end of the month. Play with Day granularity on the Project inspector to get some idea of what that might feel like.

If that's what you need, let us know and we'll put in a vote for you.

-Tom