live update for excel formula

HansVogelaar 

Here is my data sheet. My teams add a line for every new product. And when they close the Production Order they enter a date in column B. If there is no date it means that it's still not closed. Except in the case someone add an "x" into the colum D. Then it is counted as closed.

So I have the following board to track the number of open Production Order:

My problem is that the formula need to be manually updated everytime someone add a new line in my data sheet. How to update this formula automatically?

Hope you get my point.

Thanks in advance.