本文件支持并补充了ISO 17666中定义的风险管理流程在认为有必要应用定量风险评估的情况下的实施。 本文件定义了进行定量风险评估的原则、过程、实施和要求，并解释了适用于安全的概率风险评估（PRA）的细节。虽然PRA可应用于涉及成本和进度的项目风险管理，但该应用不在本文件范围内。 本文件提供了使用PRA技术评估空间计划和项目的安全或任务风险和成功的基本要求和程序。本文件适用于涉及以下内容的所有国际空间项目: -载人航天飞行器的设计； -人类居住的空间和非地面行星站的设计； -由核材料提供动力或运载核材料的航天器和运载火箭的设计； -当局或客户指示的其他项目。 这些类型的项目通常涉及可能导致公众、宇航员或飞行员或工作人员死亡或严重受伤，或关键或高价值设备和财产损失的场景、事件链或活动。对于其他类型的项目，项目管理层可自行决定是否执行PRA。

This document supports and complements the implementation of the risk management process defined in ISO 17666 in situations when the application of a quantitative risk assessment is deemed necessary. This document defines the principles, process, implementation and requirements for conducting a quantitative risk assessment and explains the details of probabilistic risk assessment (PRA) as applied to safety. While PRA can be applied to project risk management involving cost and schedule, this application is outside the scope of this document. This document provides the basic requirements and procedures for the use of PRA techniques to assess safety or mission risk and success in space programmes and projects. This document is applicable to all international space projects involving: — the design of space vehicles for the transportation of personnel in space; — the design of space and non-terrestrial planetary stations inhabited by human beings; — the design of space and launch vehicles powered by, or carrying, nuclear materials; — other projects as directed by the authorities or clients. These types of projects generally involve scenarios, chains of events or activities that could result in the death of, or serious injury to, members of the public, astronauts or pilots, or the workforce, or the loss of critical or high-value equipment and property. For other types of projects, it is intended that PRA be performed at the discretion of the project management.