The scope of this Handbook is the software metrication as part of a space project, i.e. a space system, a subsystem including hardware and software, or ultimately a software product. It is intended to complement the [ECSS-Q-80] with specific guidelines related to use of different software metrics including their collection, analysis and reporting. Tailoring guidelines for the software metrication process are also provided to help to meet specific project requirements. This Handbook provides recommendations, methods and procedures that can be used for the selection and application of appropriate metrics, but it does not include new requirements with respect to those provided by ECSS-ST-Q-80C Standard. The scope of this Handbook covers the following topics: ·ð Specification of the goals and objectives for a metrication programme. ·ð Identification of criteria for selection of metrics in a specific project / environment (goal driven). ·ð Planning of metrication in the development life cycle. ·ð Interface of metrication with engineering processes. ·ð Data collection aspects (including use of tools). ·ð Approach to the analysis of the collected data. ·ð Feedback into the process and product based on the analysis results. ·ð Continuous improvement of measurement process. ·ð Use of metrics for process and product improvement. This Handbook is applicable to all types of software of all major parts of a space system, including the space segment, the launch service segment and the ground segment software.