Root causal factors, incident investigation

To answer that question for myself, I thought about the studies I made of over 1200 incident investigation reports completed by supervisors or investigation teams. I have not had an experience with an organization in which avoiding the reality of root causal factors was an active process. By that I mean—I have not encountered a situation in which instructions were given to avoid the identification of systems causal factors. 

Recaii Whittingham s findings In many organizations, and sometimes in whole industries, there is an unwillingness to look closely into error-provocative system faults. For an incident investigation system to be effective, management must demonstrate by its actions that it wants to know what the root causal factors are. 

In the incident investigation procedure manual, the same thought is conveyed and little guidance is given on root causal factors at levels above that of the worker. 

When there is a lack of understanding about the fundamentals of incident causation and the need to identify root causal factors, supervisors, upper levels of management, and safety professionals sign off on incident reports when the reality is that those investigations were shallow and of little value. Making the additional reviews proposed here will help a safety professional define the extent of any problem and assist in crafting a course of action for improvement. 

Given an incident description, the investigator would ask why five times to get to the root causal factors and outline any necessary corrective actions. A not overly complex example follows ... 

A review of the forementioned documents will provide an inexpensive and valuable education. Now, to extend the resource list, five books on incident investigation and root causal factor identification and analysis and one Manual are referenced. There are other resources. 

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. 

Tool—A device or means used at a discrete stage of the incident investigation to facilitate understanding of event chronology, causal factors, and/or root causes. 

Causal factor identification tools are relatively easy to learn and easy to apply to simple incidents. For more complex incidents with complicated timelines, one or more causal factors can be overlooked, ultimately leading to missed root causes. Another disadvantage is that an inexperienced investigator could potentially assume that suppositions are causal factors, when in reality the supposed event or condition did not occur. 

Checklist analysis tools can be a user-friendly means to assist investigation teams as they conduct root cause analysis.h) Each causal factor is reviewed against the checklist to determine why that factor existed at the time of the incident. The Systematic Cause Analysis Technique (SCAT)(9> is an example of a proprietary checklist tool. 

Unlike the procedure followed in developing logic trees, the investigation team does not construct the tree. Rather they apply each causal factor to each branch of the predefined tree in turn, and those branches that are not relevant to the incident are discarded. This prescriptive approach offers consistency and repeatability by presenting different investigators with the same standard set of possible root causes for each incident. 

While the use of predefined trees does not directly challenge the investigation team to think laterally of other possible causes, many predefined trees present a wide range of causal factors, some of which the team may not have otherwise considered. It is therefore possible, but unlikely, that the incident could involve a novel root cause that was not previously experienced by those who developed the predefined tree. The addition of a final test based on another tool, such as brainstorming, can overcome this apparent weakness. 

Root (or primary) causes, immediate (or secondary) causes, and contributory factors are identified, analyzed, and discussed in this section of the report. As described in Chapter 9, process safety incidents are the result of many factors, and therefore singling out one cause is rarely the proper approach. Some experts indicate that if a fault tree or causal factor chart was developed as part of the investigation it should be incorporated to facilitate understanding. 

The existence of an indeterminate number of root causes may help explain some of the frustration that is occasionally expressed with standardized incident analysis procedures and software. In spite of their structured approach, these systems are fundamentally subjective. For example, one technique helps the investigation team list many of the possible causes that led to an event. Some of these causes are then identified as causal factors which are then developed into root causes. Yet the determination as to which causes are causal factors will necessarily depend on the... 

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. 

This method identifies causal factors to accident or near-miss incidents. The root causes are the underlying contributing causes for observed deficiencies that should be documented in the findings of an investigation (Tarrents, 1980). 

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