ECSS-E-TM-10-25 "System Engineering - Engineering Design Model Data Exchange (CDF)" is a Technical Memorandum under the E-10 "System engineering" branch in the ECSS series of standards, handbooks and technical memoranda. Scope and Purpose This Technical Memorandum facilitates and promotes common data definitions and exchange among partner Agencies, European space industry and institutes, which are interested to collaborate on concurrent design, sharing analysis and design outputs and related reviews. This comprises a system decomposition up to any level and related standard lists of parameters and disciplines. Further it provides the starting point of the space system life cycle defining the parameter sets required to cover all project phases, although the present Technical Memorandum only addresses Phases 0 and A. This Technical Memorandum is intended to evolve into an ECSS Standard in the future. In conjunction with related development and validation activities, this Technical Memorandum should be regarded as a mechanism for reaching consensus prior to building the standard itself. The Technical Memorandum provides the basis for creating interoperable Concurrent Design (CD) centers across the European space community. Allowing semantically consistent data exchange between CD centers. Enabling and supporting joint real-time collaborative design activities involving multiple CD centers. The initial objective of the TM is thus to act as a reference for the creation of new CD centers or upgrade of existing ones. Structure ECSS-E-TM-10-25A comprises the following parts: Clause 1: Scope Clause 2: Normative references Clause 3: Terms, definitions and abbreviated terms Clause 4: Background and concepts Includes the description of the Space Engineering Information Model (SEIM), a conceptual data model for all information needed to conduct concurrent design sessions Includes the description of the Space Engineering Reference Data Library (SERDL), an agreed collection of concurrent design organization roles, process concepts, disciplines and parameter types. These are predefined instances of SEIM concepts. Clause 5: A list of requirements that two or more parties that want to exchange data for a concurrent design activity shall comply with. Annex A: The formal definition of the Space Engineering Information Model (SEIM). Annex B: The formal definition of the Space Engineering Reference Data Library (SERDL). Annex C: The formal definition of the Web Services Interface and exchange file format. Annex D: An informative description of margins and reference frames. Software Implementations Multiple software implementations of ECSS-E-TM-10-25A exist. These software implementations allow a team of engineers to collaborate on the design of a complex system such