This standard defines the requirements for selection, control, procurement and usage of EEE components for space projects. This standard differentiates between three classes of components through three different sets of standardization requirements (clauses) to be met. The three classes provide for three levels of trade-off between assurance and risk. The highest assurance and lowest risk is provided by class 1 and the lowest assurance and highest risk by class 3. Procurement costs are typically highest for class 1 and lowest for class 3. Mitigation and other engineering measures may decrease the total cost of ownership differences between the three classes. The project objectives, definition and constraints determine which class or classes of components are appropriate to be utilised within the system and subsystems. a. Class 1 components are described in Clause 4. b. Class 2 components are described in Clause 5 c. Class 3 components are described in Clause 6. The requirements of this document apply to all parties involved at all levels in the integration of EEE components into space segment hardware and launchers. This standard may be tailored for the specific characteristics and constraints of a space project in conformance with ECSS-S-ST-00.