Month Duration - Date

[mnellsae]

I have a project that contains a 4 month task. The task is a regulation requirement, where a study must be conducted for 4 months, regardless of the # of days within a month.

So, if the task starts on 1/20, it must end on 5/20. If it starts on 2/13, it must end on 6/13.

The problem is that if I just use "4 months" as the duration in MS Project, the finish date is calculated at 80 working days after the start. So, a start date of 3/11 produces a finish date of 6/30. The actual finish date should be 7/11, and the task appears to finish almost 2 weeks before it actually will.

I can put in "89 days", and that will give me the correct finish date, but that will only work if the task falls in these months. If the preceeding tasks are delayed or finish early, the 4 month task may start in different months, and "89 days" won't work.

So, is there a way to make Project calculate a finish date by just adding 4 to the month of the start date? That way, I won't always have to check this task to make sure it's scheduled correctly as other tasks finish.

I have created a custom field as "Date1" that will calculate the date I need:

dateadd("m",3,[Start]

But, I can't figure out how to make the finish date align with this. Maybe I'm off on the wrong path. Any help would be appreciated. Thanks!

 

[mnellsae]

Sorry, I had a typo in the formula, code should read:

dateadd("m",4,[Start])

 

[MSPtrainer]

The easiest way to handle this situation is using elapsed time. It turns the time into physical number of days. To do this just put an "E" in front of the months. For example 4m should be entered as 4em. in the duration column. You should now see the number of days you are trying to achieve.

Good luck

E. Lehnert, PMP, MCT

http://www.lehnertcs.com