Event and causal factors analysis

Events and Causal Factor Analysis identifies the time sequence of a series of tasks or actions and the surrounding conditions leading to an occurrence as well as determines the causal factors. (See Chapter 9.)... 

This is a relatively brief and inexpensive book that comments on the general incident investigation process, and on several investigation and analytical techniques, such as Events and Causal Factors Analysis Change Analysis Tree Analysis and Specialized Computerized Techniques. 

The amoxmt of information required to describe effectively a complex accident is likely to be beyond tiie scope of succinct narrative summary so that some t) e of formal collation technique is to be preferred. A number of such techniques are available but Events and Causal Factors Analysis (ECFA) is the most straightforward and most generally useful. 

Events and causal factor analysis Use for multifaceted problems with long or complex causal factor chain Provides visual display of analysis process. Identifies probable contributors to the condition Time consuming and requires familiarity with process to be effective Requites a broad perspective of the event to identify unrelated problems. Helps to identify where deviations occurred from acceptable methods... 

Event and causal factors analysis includes charting, which depicts the logical sequence of events and conditions (causal factors that allowed the accident to occur), and the use of deductive reasoning to determine the events or conditions that contributed to the accident. 

In the second case study, variation tree analysis and the events and causal factors chart/root cause analysis method are applied to an incident in a resin plant. This case study illustrates the application of retrospective analysis methods to identify the imderlying causes of an incident and to prescribe remedial actions. This approach is one of the recommended strategies in the overall error management framework described in Chapter 8. 

The event and causal factors charts used by the Department of Energy as an accident (or mishap) investigation tool is basically the same tool as multilinear event sequencing (MES) and similar to simultaneous timed event programming (STEP)—all based on concepts of Ludwig Benner. It is also called causal factors analysis (CFA). 

During the operations phase, new hazards are identified by periodic inspections, worksite monitoring, audits, and appraisals. Techniques used to identify hazards during the operations phase include checklists, PET analysis, and safety studies. Accident analysis is also an important method of detecting previously undetected or uncorrected hazards. Accident analysis tools include change analysis, PET analysis, MORT and mini-MORT analysis, and event and causal factors charts. 

Techniques recommended for conducting accident analysis include change analysis, event and causal factors charts, PET analysis (or MORT or mini-... 

The accident analysis report is a narrative. It includes a description of the project and the accident, a summary of findings and recommendations, an outline of methodology, and a detailed discussion of facts, findings, and recommendations. Photographs, drawings, and an event and causal factors chart are included as illustrations. 

After completely evaluating the chart, cross-check results with the event and causal factors chart and change analysis. Reconcile any differences, use all three tools to aid in writing the formal accident report, and be careful to provide findings, conclusions, and recommendations (backed up with evidence) for each factor deemed to be less than adequate. 

The basic concept from which event and causal factors charts were developed can probably be traced back to Ludwig Benner and others at the National Transportation Safety Board. Benner developed a very similar technique called multilinear event sequencing (MES) and more recently sequentially timed events plotting (STEP). Event and causal factors charts were part of the overall MORT approach to system safety developed by W. G. Johnson for the Atomic Energy Commission in the early 1970s and further developed and taught by the Department of Energy s System Safety Development Center (SSDC). The use of the event and causal factors chart is sometimes referred to as causal factors analysis. 

Event and causal factors charts are graphic representations that basically produce a picture of an accident—both the sequence of events that led to the accident and the conditions that were causal factors. This tool works very well in conjunction with PET or MORT analysis and is used widely in the Department of Energy. 

The purpose of the event and causal factors chart is to provide a systematic accident analysis tool to aid in collecting, organizing, and depicting accident... 

Like other accident analysis techniques, the event and causal factors chart should be initiated as soon as the investigation begins and developed as evidence is collected. A detailed chart is developed during the investigation it is then reduced to an executive summary containing only key events and causal factors to serve as a report illustration. 

The event and causal factors chart is developed and expanded as new evidence and information become available. It should also be developed in conjunction with other analyses (change analysis and PET or MORT analysis), and information should be cross-checked (Fig. 19-2). Conditions that are causal factors on the event and causal factors chart should be identified as less than adequate areas on the PET, MORT, or mini-MORT chart. 

The Causal Factors Chart is a formal, and systematic, incident investigation and root cause analysis technique. The technique depicts the events and conditions leading up to an incident. It combines critical thinking, logical analysis, and graphic representations to analyze and depict an incident event scenario. It helps strncture the analysis and data gathering processes to ensure necessary and snfficient information is collected. The CFC also has been applied to Root Cause Analysis. The CFC is sometimes referred to as the Events and Causal Factors (ECF) chart. The ECF chart depicts the necessary and sufficient events and causal factors associated with a specific incident scenario. 

Causal factor analysis is used when there are multiple problems with a long causal factor chain of events. A causal factor chain is a sequence of events that shows, step by step, the events that took place in order for the accident to occur. Causal factor analysis puts all the necessary and sufficient events and causal factors for an accident in a logical, chronological sequence. It analyzes the accident and evaluates evidence during an investigation. It is also used to help prevent similar accidents in the future and to validate the accuracy of pre-accidental system analysis. It is used to help... 

On the downside, causal factor analysis is time consuming and requires the investigator to be familiar with the process for it to be effective. As can be seen later in this chapter, the accident scene may need to be revisited a number of times and areas that are not directly related to the accident may need to viewed, in order to have a complete event and causal factor chain. It requires a broad perspective of the accident in order to identify any hidden problems that would have caused the accident. 

If the information becomes too difficult to manipulate manually, the data can be entered into a computerized analysis program. Using specialized analytical software, investigators can produce an events and causal factors graphic, as well as other analytical trees or accident models. 

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