Hate to admit it but the industry both Strata and Property Management is not well supported in the area of key control by the IT systems which we use daily.
The Property Stock and Business Agents Act confers a duty of care (over keys) on property managers, as far as I know there is no specific section in the agency agreement or PSBA Act about key control.
While the locks are common property I have never heard of a building taking control of all entry door keys – you would want to think this through as doing so may leave the OC liable if there was a property loss.
Strata Manage IT.com does have a full access control system built in – look at that.