• For the frozen values: I need to historized or version the rows in the fact table using valid from and to columns, because business wants to know the value of a forecasted volume at the miles stone date, but before and after this date this value can be changed and they also want to know the current value. How you would approach this?

    Sorry I missed this. I assume that you're concerned about changes after each respective milestone date, as changes before a given date would not matter. At first blush I would have a column with the milestone date and a second for the data point at that moment. You would need the same column for that data point that would be current and could be changed of course. I don't know how many data points you need to preserve, and if it's a lot, that could be a problematic solution. But the grain of an accumulated snapshot generally represents something undergoing a process. This seems to me what you are describing.