Use the Modify Component Issues field in Regulatory Attributes Control (1.22.24) to control issues to work orders. Set this field to No to require that all items issues are on the work order BOM or are valid substitute items. Choose Yes to allow any item to be issued to the work order.

Valid substitute items are defined in Item Substitution Maintenance (13.19). When Modify Component Issues is No, issues are allowed for those items with valid substitutes.