Over the past two decades, SPA has conducted research of causal factors in hundreds of accidents utilizing human factors analysis, preliminary hazard analysis, health/environmental hazard analysis, and product safety analysis to determine most probable cause(s) for Forensic Technologies International, Cadcom Inc. (a division of ManTech International), Failure Analysis Associates Inc., the insurance community, and private counsel. In the analysis of accidents, the Fault Tree Analysis approach is utilized.
Fault Tree Analysis
SPA LLC typically utilizes a Fault Tree Analysis to determine causal relationships between the accident event and contributing factors, if any. A fault tree analysis (FTA) is a deductive, top-down method of analyzing system design and performance. It involves specifying a top event to analyze (such as a FALL), followed by identifying all of the associated elements in the system that could cause that top event to occur. Fault trees provide a convenient symbolic representation of the combination of events resulting in the occurrence of the top event. Events and gates in fault tree analysis are represented by symbols. The entire system, as well as human interactions, would be analyzed when performing a fault tree analysis. While building the fault tree and performing the analysis, a review of information regarding codes, standards, and research documents associated with processes, procedures, and equipment, along with the human interface and factual evidence relevant to the accident event, is required.
The following is an example of basic fault tree logic: