How to restrict creation or updation of Software installations through discovery

Hii All,

We have a requirement to restrict insertion or updation of software installations in cmdb_sam_sw_install table through discovery for servers, since we want this to be updated via tanium only . What will be the best approach to disable it through discovery . 

I have disabled software filter for both unix and windows under discovery configuration console , but still insertion is happening.  Not able to restrict it through  IRE  since it is not visible in class manager.

Can anyone suggest the best approach on this ?