The System-Theoretic Process Analysis (STPA) method is a recognized approach to system safety analysis. However, it still has inadequate capabilities for quantitative safety analysis. To overcome this limitation, an integrated methodology was investigated for quantitative safety analysis of the complex socio-technical system that combines a system-theoretic approach and numerical simulation. In the proposed methodology, STPA method is utilized to reveal potential unsafe control actions (UCAs) and corresponding causes based on the operational principle of the target system from systemic perspective. Moreover, the consequences of identified UCAs can be quantified and safety constraints also can be improved to prevent UCAs using numerical simulations. As a complex system, the blind shear ram preventers (BSRPs) in deepwater drilling activities, with tightly interacting diverse subsystems or components, is employed to illustrate the applicability of the methodology. The results verified that the proposed methodology could evaluate potential hazards and quantify the analysis results. These results will be helpful for the design and safe operations of the BSRP system. The developed methodology has the potential to be used for safety analyses in other process industries.

中文翻译：

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基于系统理论方法和数值模拟的安全分析综合方法


系统理论过程分析 (STPA) 方法是公认的系统安全分析方法。但定量安全分析能力仍然不足。为了克服这一限制，研究了一种结合系统理论方法和数值模拟的综合方法，用于对复杂的社会技术系统进行定量安全分析。在所提出的方法中，STPA方法用于根据目标系统的运行原理从系统角度揭示潜在的不安全控制行为（UCA）和相应的原因。此外，可以量化已识别的 UCA 的后果，并且还可以使用数值模拟来改进安全约束以防止 UCA。作为一个复杂的系统，深水钻井活动中的盲剪闸板防喷器（BSRP）具有紧密相互作用的不同子系统或组件，用于说明该方法的适用性。结果验证了所提出的方法可以评估潜在危害并量化分析结果。这些结果将有助于BSRP系统的设计和安全运行。所开发的方法有可能用于其他过程工业的安全分析。