Accounting for Emergent Failure Paths in LOPA
- Type: Conference Presentation
- Conference Type: AIChE Spring Meeting and Global Congress on Process Safety
- Presentation Date: April 2, 2019
- Duration: 30 minutes
- Skill Level: Intermediate
- PDHs: 0.50
Potential failure paths can emerge between barriers in a common threat path due what is known as âsystem effects.â That is, to the interaction between otherwise independent barriers due to common support systems (for example, Maintenance), or other Operational or Management impacts. Emergence is a system effect that cannot be identified through other methods, such as IPL (Independent Protection Layer) validation. However, Human Factors methods exist that provide a framework for discovering emergent failures between barriers due to system effects.
This paper will discuss the application of one such system technique known as âNET-HARMSâ (Networked Hazard Analysis and Risk Management System). The NET-HARMS technique is a combination of two well-established Human Factors methods, the first being HTA (Hierarchical Task Analysis) and secondly, a modified SHERPA (Systematic Human Error Reduction and Prediction Approach) as the taxonomy used to classify system failures. Both methods are easy to use and can be learned quickly with a little practice. The author has several yearsâ worth of experience applying these methods to difficult LOPA problems involving administrative controls, and will show how this analysis can be extended to include hardware barriers as well.
|AIChE Member Credits||0.5|
|Employees of CCPS Member Companies||Free|
|AIChE Graduate Student Members||Free|
|AIChE Undergraduate Student Members||Free|