Abstract:Business rules are the guide to implement S1000D, and the preconditions to make sure that all datum have the consistency, integrity and exchangeability. Based on S1000D default business rules and the BRDP, taking a civil aero-engine IETM as an example, the paper studied the business rule making process and methods, a BREX data module was generated by using Xpath statements, and the BREX was verified automatically in an IETM management system. Keyword: IETM S1000D BREX BRDP