Why is it not acceptable to have a schedule which contains activities progressed beyond data date?

Because of how the software calculates the schedule.

Comparing P6 to MSP calculations can give you a better understanding.

http://www.ronwinterconsulting.com/MS_Project_for_Construction.pdf

Khaja,

Say Today is the Data Date, 07 June 2013. You update your schedule and you are saying an activity has been completed (09 June 2013) already without any factual evidence that it is already completed? It is an anticipated event that it will be completed but not actually completed.

What if It did not happened as expected?

Experience and Planning knowledge will prevail rather than software's.

Thanks Raymund & Rafael. Yeah I got it. The actual issue is when we try to update the schedule with current data date far ahead than data date, this confusion arises. Like say we are keeping data date of schedule as 01Jun15 while the current date is 20Jun13.  So we would be aware of the few activities had completed by 20Jun13, considering this and keeping 01Jun13 as data date itself the completed activities had actualized. For the sake of argument, is this okay?

khaja,

I do this all the time. I have a weekly update cycle, so shift my data date every week. But during the week I update progress as & when I become aware of it, hence actual dates up to a week ahead of the data date.

You have to be aware of the implications on float calcs, remaining start dates, resource forecasts, etc but it is not really a problem.

My general rule of thumb is so long as you have no actual dates ahead of data date when doing reports, you won't have a problem.

As an aside: I invented a new phrase for this phenomenon, which I have managed to get into a number of planning protocols -"Factuals" (short for forecasted actuals), and it's sister phrase "Forepasts" (short for forecasts in the past) -more relevant to MS Project users.

Khaja,

You technically can't give an "actual" date of completion past the data date because it hasn't happened yet.  Any time you want to update activities you'll need to move the data date to be as current as the date you are entering.  It'd be like me saying I completed pouring concrete next week....it can't be complete because it hasn't happened yet (that's how the program looks at the data date).  Does that make sense?

Hi Gary

I love the word Forepast.

Its like Rumsfeld's Known Unknowns.

It should be in every planning text book.

Best regards

Mike Testro

this is woul dbe back to the future you must set your mind at the data date.