Causal analysis incident investigation

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. 

Eliminate other distractions from the room if possible. Do not allow the witness to see any documents, such as causal factor charts, fault trees, showing the incident investigation team analysis of the occurrence. This may he appropriate for later interviews when only specific information is needed or a specific time gap is being filled in. 

CCPS Typical Trending Analysis Results Incident Investigation (Historical Causal Information)... 

Each company s management style and safety systems have strengths and weaknesses. These strengths and weakness tend to influence the types and severity of incidents that might occur. An analysis of incident investigation findings in terms of causal factors, immediate causes, contributing causes,... 

If hazard identification and analysis do not relate to actual causal factors, the resulting corrective actions proposed will be misdirected and ineffective. A superior quality of incident investigation is required to identify and evaluate actual causal factors so that appropriate corrective actions can be taken. 

Five of the 15 forms received require entry of codes for causal factors, incident types, and injury t)q)es. When computer analysis programs first became available, I had been an aggressive promoter of the entiy of causal factor codes for later analysis. That proved to be inappropriate because accurate causal data are often not included in supervisors investigation reports or in insurance claims reports. Now, I recommend that computer-based analysis systems not include provision for causal data entry. They serve analysis purposes quite well for types of accidents, injury types, parts of body injured, and identification data (location, age, job title, etc.). 

Setting the above knowledge and proposals together leads to integrated incident investigation procedure which is stUl based on the timeline development, causal factor identification and causal factor chart development, but which allows the determination of different Incident Cause Level for each of multiple causes. If the Incident Cause Level of specific cause is outside the internal safety management, the apph-cation of non-hnear analysis method is recommended. 

LuxhaJ, XT. (2003). Probabilistic Causal Analysis for System Safety Risk Assessments in Commercial Air Transport. Workshop on Investigating and Reporting of Incidents and Accidents (IRIA). Williamsburg, Virginia, USA, National Aeronautics and Space Administration (NASA). 

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. 

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. 

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. 

Other accident analysis and investigation approaches that make explicit reference to supervision as a potential causal factor include AcciMaps (Svedung and Rasmussen, 2002), which diagrams company management and technical, operational, and management failure levels, and the Incident Cause Analysis Method (ICAM) (BHP Billiton, 2001), which addresses inadequate supervision and poor supervisor or worker ratio error modes. 

The inquiry should include a root-cause analysis of a number of incidents, looking for patterns. This increases the probability that the behaviors are indeed critical. We would add that most of the hundreds of incident investigations we have seen do not get to root causes. Krause is clearly aware of this and provides an excellent methodology to improve this process. He recommends the causal-tree method. This particular method for incident investigation is described in Chapter 5. 

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. 

Analysis, that can assist with the identihcation of causal factors. The concepts of incident causation encompassed in these tools are fundamental to the majority of investigation methodologies. (See Chapter 3 for information about the Domino Theory, System Theory, and HBT Theory.) The simplest approach involves reviewing each unplanned, unintended, or adverse item (negative event or undesirable condition) on the timeline and asking, Would the incident have been prevented or mitigated if the item had not existed If the answer is yes, then the item is a causal factor. Generally, process safety incidents involve multiple causal factors. 

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. 

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. 

The tool helps the investigator to understand and focus on the failed harriers, which are normally identified as causal factors. These failed harriers may need to he strengthened, replaced, or supplemented, especially where weak administrative controls are highlighted. Even successful barriers that prevented more serious consequences may require reinforcement. Therefore, barrier analysis can give the investigator valuable insights into how the incident happened and some of the multiple causes that need corrective action to prevent recurrence. 

The essential elements of pharmacovigilence during clinical trials of an investigational compound span from adverse event identification through characterization and analysis. Identification is focused on treatment-emergent adverse events. These events can then be characterized by incidence, prevalence, severity, seriousness, and relationship to the study drug (causality). The data can then be examined to identify potential risk factors and markers with which to anticipate the occurrence of an adverse event. 

To focus its analysis, the committee decided to examine events with the following characteristics (1) sufficient investigation had already been done to provide a basis for analysis and (2) the event could have had potentially serious outcomes, was complex in nature, was well documented, and provided a rich source of potential causal factors. With this as a rationale, the committee examined five dissimilar incidents in significant detail (Table 2-1). 

The committee s analysis was conducted on several levels. First, members investigated the causal factors for each of the seven events listed in Tables 2-1 and 2-2. They then developed a notional causal tree for each of the two events in Table 2-2 that were analyzed in depth. For illustrative purposes, a causal tree developed by the committee for the December 3-5,2000, incident at JACADS appears at Appendix F. The tree is a standard tool in reliability analysis and is particularly useful in human reliability analysis where operator actions contribute either positively or negatively to an incident. Lastly, the committee provides a series of general and specific observations about the events. 

The committee s analysis of the seven chemical events listed in Tables 2-1 and 2-2 showed that there were multiple causal factors for all of the selected events. (Note the committee could detennine causal factors only for incidents for which sufficient investigation data were available.) Rather than being specified for each incident, the causal factors identified by the committee are grouped into the following generic categories ... 

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