I had a lot of question about the Topic I will write about today. Basically it is about relations between Resource (with no Calendar, or, to be more precise, which has Standard Calendar assigned), and specific Task with Specific Calendar working time.
I will explain this with MS PROJECT 2016 with Very simple Project, which has only one Task, and only one Resource.
Task has 1 day Duration. Suppose, that for some reason work on Task can be done only from 08:30 to 13:30, and from 14:30 to 17:30 (let’s say for security reasons), and this will apply only for this Task.
First, I will create separate Calendar:
OK! Now I will assign Task Calendar to the Task:
and I will get:
As you can see, duration for the Task is 1 day, but for the Project is 0,94 days (and the Project has only one Task).
As you can see on the right side of the screen Task will be worked on from 08:30 to 17:00.
How to explain this? first, if you choose File->Options->Schedule you will notice this:
In Task Calendar work can start at 08:30, so it will start at that time. On the Task Calendar, work can end at 17:30, but because the Schedule (see screenshot above) says that end time is at 17:00, the work will end at that time. So, the Task will be worked on from 08:30 to 17:00 with on hour break from 13:30 to 14:30 (according to the Task Calendar9, and that is 7,5 hours of total work. But, because on Schedule Option it says that it is 8 hours per day, duration for the Project is calculated as 7,5 / 8 = 0,94.
Now I will assign Resource – John to the Task. he has no specific calendar, so he is supposed to work from 08:00 to 12:00 and from 13:00 to 17:00. When I assign him, I will get this (I will show you on the Task Usage View):
- Monday, 10.07.2017:
- Tuesday, 11.07.2017:
I will explain this result, step by step:
- Task Duration is 1 day, and this is 8 hours of work to be done on it (see 3 pictures above)
- John can work from 08:00 to 12:00 and from 13:00 to 17:00
- Task Calendar says that on Task work can be done from 08:30 to 13:30 and from 14:30 to 17:30
- According to that, John will start to work at 08:30 (because of Task Calendar) and he will work to 12:00 (because of his Calendar), and this is 3,5 hours. He will continue at 13:00 (because of his Calendar) and he will work to 13:30 (because of Task Calendar) and this is 0,5 hours. Then he will continue at 14:30 (because of Task Calendar), and he will work to 17:00 (because of his Calendar) and this is 2,5 hours. So he will work 3,5+0,5+2,5= 6,5 hours at Monday. At Tuesday John has to work remaining 1,5 hours and he will start to work at 08:30 (because of Task Calendar) and he will work to 10:00.
- Duration for the Project says that it is 1,19 days. It is confused. Why? Because you will think that the calculation should be 6,5 hours on Monday /8 hours per day (in Schedule options) + 1,5 hours on Monday /8 hours per day (in Schedule options) = 1. But MS PROJECT calculates it like: Monday = 1 day because it was worked on it the whole day (whenever it was possible to work!). On Tuesday it was worked 1,5 hours of 8 available, so it is 1,5/8 = 0,19. Do the Total duration is 1 (Monday) + 0,19 (Tuesday) = 1,19 days
To conclude, it can be confusing, but you should get use to it.