Inconsistent Duration column for the same date ranges

[ravl13]

Hi,

I've noticed that when I have task dates that are on Saturdays and Sundays, the Duration column in the project becomes inconsistent. I have a screenshot below

http://imgur.com/HXm28zU



We can see that in row 2 for the Project Management task, there is a duration of 190 days. But row 3 below it for the Project Manager task says a duration of 192 days. Clearly there's some kind of wonky calendar thing going on here whenever there's weekend days involved (it's consistent when the start and end dates are weekdays), but I don't know where calendar settings are stored. Where can I look for the configuration/setting that is causing this weirdness, and how do I apply consistent calendar settings across the entire project?

[JulieS]

The duration of a task is working time based upon the calendar in use. So, if you have resources assigned to tasks - the calendar in use is their calendar. On summary tasks the project calendar (set in Project Information) is used to calculate duration.

In the attached picture, the only task shows a longer duration than the single summary task. The resource assigned to the task has a calendar with Saturday marked as working days. Based upon the resource's calendar, there are 21 working days between July 28 and August 20 - counting Saturdays. However the project calendar only has working days Monday through Friday - so there are only 18 working days using that measure.

When dealing with resources with different calendar definitions, it may be more meaningful to stop talking about "duration" and start talking start and finish dates plus work.

I hope this helps.

[ravl13]

The projects and resources are actually using the same "Standard" MS Project calendar. But the problem seems to arise from the fact that the subtasks are set to manually scheduled mode, while the task rows are automatically scheduled. Manually scheduled rows automatically include a start date of Sunday as a working day since you manually set that date (even though its not on the calendar), but the parent "automatic scheduled" row that changes to match the new start date does NOT include Sunday as a working day because it's not on the calendar.

[JulieS]

I agree with your statement. As shown in the picture I attached, it can also occur with autoscheduled tasks and differing calendars. Manually scheduled tasks can be entering with start and/or finish dates during what is usually non-working time.

My best suggestion is to use manual scheduled tasks only during early planning. I switch to autoscheduled well before I start assigning resources.