Hazard Control Verification: Where Hazard Analysis Becomes Safety Assurance

摘要

In a hazard analysis, the system safety practitioner proposes various controls for reducing or eliminating the risk associated with each identified hazard. The managing activity decides on the acceptability or unacceptability of the associated risks and the necessity of implementing each of the proposed hazard controls. From that point on, effective safety assurance depends, to a large extent, on hazard control verification. Without adequate verification, the hazard analysis and safety review process are essentially reduced to exercises on paper only, and the risk reduction effort is compromised. This paper first explores the real meaning of hazard control verification and its importance in the overall safety assurance process. Hazard control verification should consist of two primary sub-processes: validation of a proposed hazard control's effectiveness if implemented, and assurance of actual implementation before release of the system for production, fielding, or operation. Verification language from various system safety sources is cited and discussed. Some practical examples of hazard control verification are reviewed. Finally, recommendations are made for improving the system safety community's practice of hazard control verification. The author's conclusion is that hazard control verification is the essential link between on-paper analysis and physical or administrative action to reduce or eliminate risk.