MATDOC must be there if the S/4HANA On Premise system is 1511 version, it is not there in 1503 or Simple Finance.
Checking the version is simple - just goto System Status from menu and check Installed Software.
If its 1511 then it should show S4CORE 100 under Installed Software Component Version and Installed Product Version as 1511.
If its Simple Finance system then it would show SAP_APPL 617 instead of S4CORE 100.