Fault tree analysis investigation tools

The earliest logic trees were based on engineering fault tree analysis methods. Today, companies use a number of variations or combinations of logic trees and call them by different names, such as Why Tree,< 9) Causal Tree,(20,21) Cause and Effect Logic Diagram (CELD),<22) and Multiple-Cause, Systems-Oriented Incident Investigation (MCS011).<23,24) tools have more similarities than differences. 

Causal factor identification is relatively easy to learn and apply to simple incidents. For more complex incidents with complicated timelines, one or more causal factors can easily be overlooked, however, which inevitably will result in failure to identify their root causes. There are a number of tools, such as Barrier Analysis, Change Analysis, and Fault Tree Analysis, that can assist with bridging gaps in data and the identification of causal factors. Each of these tools has merits that can assist the investigator in understanding what happened and how it happened. 

Fault tree analysis was created in the military industry during the Minuteman missile program. It is a graphical tool used to identify the faults in a system and which events lead to that catastrophic event they have proven so useful that other industries are starting to use them. The chemical industry is starting to use fault trees, especially in accident investigation. 

Analysis methodologies and techniques—Are sometimes put in the appendix. It describes the kind of safety analysis tools that were used in the course of the investigation (e.g., fault tree analysis, FMECA) and how and why they were used. 

MORT analysis. A detailed, comprehensive 1,500-item fault tree used primarily for mishap investigation. This valuable tool serves as a graphic guide for organizing and conducting an investigation and for writing the accident report. It may also be used as an appraisal or accident-prevention tool. 

Fault trees are very diverse and can be used in many ways. They are one of my most favorite safety analysis tools. I have used them for such diverse activities as understanding integrity management of an upstream oil pipeline system, employee and management actions taken during a plutonium spill at a laboratory, and the Sydney, Australia, Waterfall rail accident investigation. 

Having defined the dependability criteria within the specification, the purpose of this activity will include an investigation of the relationship between the development lifecycle (including the proof of safety invariants, refinement of the dependability criteria/perspectives and validation/verification approaches) and the dependability lifecycle which includes safety analysis (eg, the relationship between fault trees, proof of safety invariants, and static analysis tools), fault detection/protection and failure detection/containment. 

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