OPJK Material Availability Settings

HI Gurus,

I need to ensure, that my users can't issue a Requisition without a Material Number assigned.

Currently they can do in CJ20N by releasing a a Network activity. This is because in OPJK we have "No Check" ticked for Material Availability.

So we need to cnahge the settings.

The question is what better to choose between:

      - Status check (if I tick this one, does it mean system will allow a Req without a material number? what does "missing part status" mean?)

     - Check Material availability when saving order(if I tick this one, does it mean system will allow a Req without a material number? is that causing performance issue easily?:)

Thank you,

Daria