This European Standard establishes the requirements for the verification of a space system product. It specifies the fundamental concepts of the verification process, the criteria for defining the verification strategy and the rules for the implementation of the verification programme. It includes also in annexes A and B the description of the required documentation (i.e. DRDs) and some guidelines on specific aspects of the verification process such as the model philosophy definition. This European Standard is intended to apply to different products at different levels (i.e. from a single equipment to the overall system). It is applicable to both the customer and the supplier of the product during all product phases. The application of these requirements to a particular project is intended to result in an effective product verification and consequently to a high confidence in achieving successful product operations for the intended use. In preparing this European Standard the following goals have been considered to facilitate its application, effective use and tailoring: - definition of an envelope of the sets of minimum verification requirements applicable to the different products, so that tailoring is a selection (in reduction) process; - clear identification of mandatory requirements, tailorable requirements and recommendations by means of the appropriate use of "shall", "should" and "may" respectively; - text defining requirements should be selfstanding to the greatest possible extent, to allow direct tailoring.