In 11i requisition approval workflow (REQAPPRV), 'Build Default Approval List' function i.e. PO_APPROVAL_LIST_WF1S.BUILD_DEFAULT_APPROVAL_LIST builds the default approval list based of position/emp supervisor hierarchy. It then calls po_approvallist_s1.VerifyAuthority() which invokes PO Document Approval Manager. PO Document Approval Manager is also invoked after requisition is approved in 'Does Approver Have Authority?' function.
I believe VerifyAuthority() is the place where approval limits are checked. Please direct me to exact package which does check on approval limit vs requisition total. Also what is the purpose of PO Document Approval Manager. One of the metalink notes says Doc Manager in R12 is coded in PL/SQL. That R12 code might be useful.
P.S: I found poreq.verifyauthority(), but it is checking only for DOCUMENT_TOTAL in po_control_rules. What about the ACCOUNT_RANGE?