AbstractThis paper describes the System and Software Requirements Management experience and lessons learned during the development of the Ranger Unmanned Air Vehicle (UAV) System. The Ranger Project involved a multi national collaborative effort, which despite its geographical dispersion was able to successfully produce a large scale, real time system with a complex set of requirements, testing stipulations and an extensive set of formal documentation.Requirements Management (RM), the focus of this study utilized a Commercial‐Off‐The Shelf (COTS) Data Base Management System (DBMS) and an in‐house developed man‐machine front‐end which supervised and controlled the access to the DBMS. These were used to elicit System requirements which were provided to the hardware and software engineers for further decomposition. Requirements, design, and testing documents were generated from the DBMS and from a back‐end document generator.