As a proactive safeguard, inherent safety has been regarded as the top hierarchy for loss prevention and risk management due to its salient features in eliminating or significantly reducing risks at source rather than mitigating them by add-on protections. Simultaneously, various assessment tools have been developed for ranking and selecting inherently safer designs or modifications. However, there still lacks a metric that can systematically incorporate various hazardous factors, which may hinder most industries from utilizing it to a full extent. To address this limitation, this work developed a Systematic Inherent Safety Metric (SISM) for measuring the inherently safer modifications. Firstly, the conceptual framework of SIS was proposed based on 5M1E (man, machine, material, method, measurement, and environment). Subsequently, analytic hierarchy process and fuzzy comprehensive evaluation were adapted to conduct risk identification and assessment. Finally, taking chlorine liquefaction process as a case study, the applicability and efficacy of SIS were validated based on PDCA (plan-do-check-action) cycle. The results show that the SISM value has improved from the relatively dangerous (RD) to the relatively safe (RS) after implementing SIS, thus demonstrating that the revised design is inherently safer than the base design.

作为一种积极的保障措施，固有的安全性被视为消除损失和风险管理的最重要层次，因为其显着的特征是从源头消除或显着降低风险，而不是通过附加保护措施来减轻风险。同时，已开发出各种评估工具，用于对本质上更安全的设计或修改进行排名和选择。但是，仍然缺乏一种可以系统地纳入各种危险因素的指标，这可能会阻碍大多数行业充分利用它。为了解决此限制，这项工作开发了系统固有安全性度量标准（SISM），用于测量本质上更安全的修改。首先，基于5M1E（人，机器，材料，方法，测量和环境）提出了SIS的概念框架。后来，运用层次分析法和模糊综合评价法进行风险识别与评估。最后，以氯气液化过程为例，基于PDCA（plan-do-check-action）循环验证了SIS的适用性和有效性。结果表明，在实施SIS后，SISM值已从相对危险（RD）提高到相对安全（RS），从而表明，修订后的设计从本质上比基本设计更安全。