Causal factor analysis events

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. 

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

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. 

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. ... 

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. 

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. 

Molecular analysis of the interaction between plants, microbes, and soil components may help us understand the causal relationships of events taking plaee in the rhizosphere. Nevertheless, due to the necessity to simplify the experimental approaches, we still do not have the complete picture that takes into ae-count the relative weight of each factor. 

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. 

The design of most process plants relies on redundant safety features or layers of protection, such that multiple layers must fail before a serious incident occurs. Barrier analysis ) (also called Hazard-Barrier-Target Analysis, HBTA) can assist the identification of causal factors by identifying which safety feature(s) failed to function as desired and allowed the sequence of events to occur. These safety features or barriers are anything that is used to protect a system or person from a hazard including both physical and administrative layers of protection. The concepts of the hazard-barrier-target theory of incident causation are encompassed in this tool. (See Chapter 3.)... 

Once the actual incident scenario is understood and its multiple causal factors identified, this information may be used to determine the incident s root causes. One means of performing root cause analysis involves the use of ready-made, predefined trees. A predefined tree provides a systematic approach for analyzing and selecting the relevant elements of the incident scenario. It is a deductive approach, looking backward in time to examine preceding events necessary to produce the specified incident. 

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). 

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