Answer
Query the Report Definition navigation window for the report to find its underlying report view/ID — for Shop Order Work In Progress, this is SHOP_ORD_WIP_REP, and you can inspect that view's own definition directly to see the SQL behind what's displayed. If you also need the actual report method/procedure logic (not just the view), there's a consistent naming convention: swap the '_REP' suffix for '_RPI' — for this report, that gives SHOP_ORD_WIP_RPI, which is the corresponding report-implementation package. This _REP-to-_RPI naming pattern generally holds for tracing any standard operational report's underlying view alongside its implementation logic, not just this specific one.