The ECSS standards of the Q branch describe a set of requirements for a Product Assurance programme to be implemented throughout the phases of a space project. This document defines the Product assurance management requirements for space projects. This document is structured in two main parts, the first part presenting the principles of Product Assurance management and the second providing the detailed requirements. In addition, the expected content of the Product Assurance plan is specified in Annex A. Information on the expected delivery of ECSS PA management discipline documents per review is provided in Annex D. This Standard is applicable to all space projects. This standard may be tailored for the specific characteristic and constrains of a space project in conformance with ECSS-S-ST-00.