ECSS-Q-ST-30C Rev.1 – Dependability (15 February 2017)

This Standard cancels and replaces ECSS-Q-ST-30C (6 March 2009).



This Standard defines the dependability assurance program and the dependability requirements for space systems. Dependability assurance is a continuous and iterative process throughout the project life cycle.


The ECSS dependability policy for space projects is applied by implementing a dependability assurance program, which comprises:

  • identification of all technical risks with respect to functional needs which can lead to non-compliance with dependability requirements,
  • application of analysis and design methods to ensure that dependability targets are met,
  • optimization of the overall cost and schedule by making sure that:
    • design rules, dependability analyses and risk reducing actions are tailored with respect to an appropriate severity categorization,
    • risks reducing actions are implemented continuously since the early phase of a project and especially during the design phase.
  • inputs to serial production activities.


The dependability requirements for functions implemented in software, and the interaction between hardware and software, are identified in this Standard.

NOTE 1 The requirements for the product assurance of software are defined in ECSS-Q-ST-80.
NOTE 2 The dependability assurance program supports the project risk management process as described in ECSS-M-ST-80

This Standard applies to all European space projects. The provisions of this document apply to all project phases. Depending of the product category, the application of this standard needs to be checked and if needed tailored. The pre-tailoring table in clause 8 contains the applicability of the requirements of this document and its annexes according to product type.

This standard may be tailored for the specific characteristics and constraints of a space project in conformance with ECSS-S-ST-00.



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