today I will explain something that can seems as a bug, but it is not in Microsoft Project for the Web! It is a bit tricky, and I got an explanation directly from Microsoft.
Let me show you!
Firs I will setup a calendar template from 09 AM to 01 PM:
I will use this Generic Resource to create the Calendar Template:
Now I will setup Resource calendar for Ellen which will be from 09:00 AM to 05:00 PM:
Let me create a simple Project, using previous Calendar template:
Finally I will create a single Task with 1 day Duration:
As you can see Start date is 1/4/2021 (at 09:00 AM which cannot be seen because I couldn’t grab it, but if you hoover mouse on start date you will se this), and End date is 1/5/2021 at 01:00 PM. WHY?
Project defines one day of duration as 8 hours of work (I.e. the scheduling engine ensures there is time in the project calendar for 8 hours of work). Given my calendar, each working day can only support 4 hours of work (according to the project calendar). Therefore, the scheduling engine is scheduling 8 hours of working time, which takes place over 2 days on my project calendar (as there are only 4 hours of work each day).
Now I will assign Ellen to the Task and I will get:
As you can see, Effort is 12 hours. WHY?
The scheduling engine is scheduling 1 day of duration according to the project calendar. Therefore, as above, the task is scheduled from 1/4/2021 9am – 1/05/2021 1pm as that is 8 hours of work according to the project calendar
After the task is scheduling according to the project calendar, the effort is calculated based on the resource calendar. Effort is determined by scheduling work for the resource any time between the task start and task finish when the resource can work. Therefore, Ellen is scheduled to work 1/4/2021 9am-5pm (even though 1pm-5pm is outside the project calendar) AND 1/5/2021 9am-1pm. This results in 12 hours of work for Ellen.
It seems a little bit confusing, and it is confusing. But, you must remember this logic when you are building a schedule like mine.