Though not stated explicitly, if I understand correctly the focus of efforts are in Sheet1.

While I know how TREND and FORECAST functions work I am not always confident in how to apply them in statistically sound ways in all situations. This is one of those.

Three things I note:
  1. If you are not aware of it in Q16 the array formula is returning 5 values in memory. To see them click the formula bar and hit the F9 function key. Which of these are of interest?
  2. In column O there is an equation that contains some constants. What is the significance of that formula and where do the constants come from?
  3. In column G starting at G20 there is a TREND function that uses relative range referencing. I don't know enough about the proactive mission or use of TREND to know if this is sound application.

At this point I don't even know what questions to ask.

That said I am going to consult with the forum community. We have some business/statistics saavy members. Perhaps a few of these will come to our rescue.