If you want to participate in the QS scheme as an operator of mobile milling and mixing plants, you can have a QS inspection performed. To do this, directly contact a certification body that organizes all the necessary steps for you and carry out the inspection.
You can see which certification bodies are allowed in the QS scheme from this list.
If you are already certified according to another feed standard than QS, there may be the possibility to participate in the QS scheme via a recognition. Which standards are recognized by QS and how the delivery into the QS scheme is made possible can be found in Annex 9.1 of the Guideline Feed Sector.