Not possible in my opinion!
What you could do is to measure pressure loss in an isolated part over time. (The isolated part could be the complete system or a part).
This would give you the average volume loss at a certain pressure, which again could give you a comparison to the loss through a circular hole with a certain diameter.
In addition to the fact that even a 1 or 2 mm hole will give you a considerable loss at a normal pneumatic pressure, I also completely agree with you.
Any loss costing money is a waste if normal sensible good maintenance, improved layot and correct equipment could prevent it. (Remember also to calculate cost of downtime, not only pressure production!)
To try a pun: Its' not the size of the hole that counts, but the amount of mony you have to put into it!