Safety assessment has a primary role in hazardous operations. Most studies on safety assessment focus on risk and accident modeling, in which safety is absent. These top-down methods are highly dependent on the occurred accidents to establish accidental scenarios, which may make the assessment approach lagging behind the evolving modern systems. Moreover, this “special to general” logic is scientifically suspect in safety assessment. There is a call for the development of safety assessment methods in the presence of system safety to complement risk-focused safety analysis. These methods should provide a framework based on a bottom-up approach to examine system safety from the operational perspective. This paper has attempted to provide a potential solution. In particular, a novel concept of safety entropy is proposed to integrate with The Functional Resonance Analysis Method (FRAM), which is used to form the qualitative understanding of a system. A formula consisted of safety entropy, functional conformability, and system complexity has been established to determine the spontaneity of the safety state-changing process. The proposed method is applied to the safety assessment of a propane feed-control system. The results show the applicability of the method. Nevertheless, the model still needs to be further improved to fulfill better support for safety-related decision problems.

安全评估在危险操作中具有主要作用。大多数关于安全评估的研究都集中在缺乏安全性的风险和事故建模上。这些自上而下的方法高度依赖于发生的事故来建立事故场景，这可能使评估方法落后于不断发展的现代系统。此外，科学上在安全评估中怀疑这种“特殊到一般”的逻辑。呼吁在存在系统安全性的情况下开发安全评估方法，以补充针对风险的安全性分析。这些方法应提供一种基于自下而上的方法的框架，以便从操作的角度检查系统安全性。本文试图提供一种潜在的解决方案。尤其是，提出了一种新的安全熵概念，用于与功能共振分析方法（FRAM）集成，以形成对系统的定性理解。建立了由安全熵，功能一致性和系统复杂度组成的公式，以确定安全状态更改过程的自发性。该方法应用于丙烷进料控制系统的安全性评估。结果表明了该方法的适用性。尽管如此，该模型仍需要进一步改进，以更好地支持与安全相关的决策问题。建立了系统复杂性来确定安全状态更改过程的自发性。该方法应用于丙烷进料控制系统的安全性评估。结果表明了该方法的适用性。尽管如此，该模型仍需要进一步改进，以更好地支持与安全相关的决策问题。建立了系统复杂性来确定安全状态更改过程的自发性。该方法应用于丙烷进料控制系统的安全性评估。结果表明了该方法的适用性。尽管如此，该模型仍需要进一步改进，以更好地支持与安全相关的决策问题。