With Quantity as control method set on the control point... 

the system actually prompts the user for quality check for each batch of done quantity.

In the case of a MO, you should therefore produce the units one by one...

and create a backorder for each new unit.

This also gives you a better follow-up on the production of each item.

One way to enforce that is to apply serial numbers on the product.

Dear Frédéric,

many thanks for your answer

I also considered this option but this is not suitable in real life.

There is the same problem with serial number when producting several products at a time you have to create individual MO for each product just to be able to assign the SN

Regards

Maurice