Causal factor analysis

One approach is to mesh all investigation and root cause analysis activities under one management system for investigation. Such a system must address all four business drivers (1) process and personnel safety, (2) environmental responsibility, (3) quality, and (4) profitability. This approach works well since techniques used for data collection, causal factor analysis, and root cause analysis can be the same regardless of the type of incident. Many companies realize that root causes of a quality or reliability incident may become the root cause of a safety or process safety incident in the future and vice versa. 

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). 

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. 

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.)... 

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. 

Identifying the direct cause of an accident is optional because it is not necessary to complete a causal factor analysis. However, the direct cause should be identified... 

Events are occurrences that take place in order for a task to be completed. In the case of causal factor analysis, events describe a single occurrence, and are short, to the point, and contain detail. The level of detail depends on the task that is performed. For example, The plane descended 200 feet, not The plane lost altitude and the pilot went by proper procedures to regain altitude. It is up to you, as the investigator, to establish that level of detail. 

Events should be used in a causal factor analysis only if they pertain to the accident. If the event is not pertinent to the accident, exclude it from the analysis. For example, do not include The worker called her husband on her lunch break. However, do include The worker lifted the 100-pound block over her head, which led to her hurting her back. ... 

USING CAUSAL FACTOR ANALYSIS (EVENT FACTOR CHAINS OR CHARTING)... 

This questioning should then be repeated for each and every event and condition, where applicable, and reviewed by others to ensure that nothing has been overlooked. Once everyone has agreed on all the results of the questioning, then your Causal Factor Analysis is complete. 

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. 

Although an Internet search will reveal a large number of companies offering consulting services on root causal factor analysis, I am listing two that have published books on the subject, whose authors have a known history with respect to occupational safety and health ... 

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. 

Fukushima Daiichi accident - technical causal factor analysis, EPRI, Final Report, March... 

These four steps cover all phases of the occurrence investigation process. Thus, Kepner-Tregoe can be used for more than causal factor analysis. Separate worksheets (provided by Kepner-Tregoe) provide a specific focus on each of the four basic steps and consist of step-by-step procedures to aid in the analyses. This systematic approach prevents overlooking any aspect of concern. As formal Kepner-Tregoe training is needed for those using this method, a further description is not included in this book. 

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... 

Identifying the direct cause of an accident is optional because it is not necessary to complete a causal factor analysis. However, the direct cause should be identified when it facilitates understanding of why the accident occurred, and it is useful in developing lessons learned fiom the accident. The direct cause is also used when writing up the accident report and filling out an accident report form. 

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