Multi Zone Sourcing (MZS) is about qualifying a supplier at a worldwide level. Account property can be marked "MZS" if you follow some rules.
MZS qualification is used only for TG / TS / CAPEX
Open an account property.
Edit this account property.
In the Geographical axis, fill in "WORLD" and choose "Yes (Forced)" in the field "TG/TS MZ Sourcing".
Make sure the following fields are set to "Yes":
Save your account property.
Find back all suppliers with MZS qualifications, with the corresponding Listview.
Edit this account property
With this method, you need to fill in an Account Qualification Process. (A1413 - Qualification process (advanced))
In the Geographical axis, fill in "WORLD" and choose "Yes" in the field "TG/TS MZ Sourcing".