Cause analysis

Check whether a documented system is in place, which covers the reporting, investigation, root cause analysis and corrective actions taken. 

FMEA is particularly suited for root cause analysis and is quite useful for environmental qualification and aging analysis. It is extensively used in the aerospace and nuclear ]iowei indiistrii-s but seldom used in PSAs, Possibly one reason for this is that FMEA, like parts count. ,s not chrectlv suita lundant systems such as those that occur in nuclear power plants Table i 4... 

PHECA Potential Human Error Cause Analysis Kirwan, 1992... 

Burdick, G. R., and N. H. Wilson, and J. R. Wilson, COMCAN - A Computer Program for Common Cause Analysis, INEL ANCR-1314, May. 

Auditor has to advise supplier to conduct root cause analysis on all NCs. 

You will be required to perform a root cause analysis on each detected nonconformity. 

In addition to incident reporting systems, root cause analysis techniques can be used to evaluate the causes of serious incidents where resources are usually available for in-depth investigations. A practical example of root cause investigation methods is provided in Chapter 7. 

Chapter 6 discusses the ways in which feedback for operational experience can be enhanced by improved data collection and root cause analysis tech-... 

Root cause analysis systems, intended to provide in-depth evaluations of major incidents... 

This section discusses the company culture that is necessary to support effective data collection and root cause analysis. 

The types of data required for incident reporting and root cause analysis systems are specified. Data Collection practices in the CPI are described, and a detailed specification of the types of information needed for causal analyses is provided. 

However, in the case of a root cause analysis system, a much more comprehensive evaluation of the structure of the accident is required. This is necessary to unravel the often complex chain of events and contributing causes that led to the accident occurring. A number of techniques are available to describe complex accidents. Some of these, such as STEP (Sequential Timed Event Plotting) involve the use of charting methods to track the ways in which process and human events combine to give rise to accidents. CCPS (1992d) describes many of these techniques. A case study involving a hydrocarbon leak is used to illustrate the STEP technique in Chapter 7 of this book. The STEP method and related techniques will be described in Section 6.8.3. 

In the case of root cause analysis systems, more comprehensive evaluations of PIFs will normally be carried out as part of a full-scale human factors audit. This could make use of the types of comprehensive PIF evaluation methods described in Chapter 2 (see Section 2.7.7 and Figure 2.12). 

For a major incident investigation using a comprehensive root cause analysis system, teams will be formed to acquire information relevant to determine the structure and analyze the causes in depth. In addition to evaluations of the immediate causes, imderlying causes are likely to be evaluated by investigations in areas such as safety and quality management. Both paper- and computer-based systems will be used to acquire and record information for subsequent detailed analyses. 

In the following sections, a number of methodologies for accident analysis will be presented. These focus primarily on the sequence and structure of an accident and the external causal factors involved. These methods provide valuable information for the interpretation process and the development of remedial measures. Because most of these techniques include a procedure for delineating the structure of an incident, and are therefore likely to be time consuming, they will usually be applied in the root cause analysis of incidents with severe consequences. 

Identify human performance difficulties for Root Cause Analysis... 

Workforce Support for Data Collection and Incident Analysis Systems Few of the incident investigation and data collection systems reviewed provide any guidelines with regard to how these systems are to be introduced into an organization. Section 6.10 addresses this issue primarily from the perspective of incident reporting systems. However, gaining the support and ownership of the workforce is equally important for root cause analysis systems. Unless the culture and climate in a plant is such that personnel can be frank about the errors that may have contributed to an incident, and the factors which influenced these errors, then it is unlikely that the investigation will be very effective. 

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 case study has documented the investigation and root cause analysis process applied to the hydrocarbon explosion that initiated the Piper Alpha incident. The case study serves to illustrate the use of the STEP technique, which provides a clear graphical representation of the agents and events involved in the incident process. The case study also demonstrates the identification of the critical events in the sequence which significantly influenced the outcome of the incident. Finally the root causes of these critical events were determined. This allows the analyst to evaluate why they occurred and indicated areas to be addressed in developing effechve error reduchon strategies. 

To gather information about the factors which contributed to the above incident, interviews were held with the workers and their management. Relevant documentation such as standard operating procedures and documentation relating to the incident was also collected. A task analysis (see Case Study 3) of the job of the top floor person was carried out in order to examine the operations involved and the factors which could affect job performance. Two techniques were used for the analysis of this incident, namely variation tree analysis and root cause analysis. 

This involves the development of data collection and root cause analysis systems as described in Chapter 6. 

Armstrong, M. E., Cecil, W. L., Taylor, K. (1988). "Root Cause Analysis Handbook." Report No. DPSTOM-81, E. I. DuPont De Nemours Co., Savannah River Laboratory, Aiken, SC 29808. 

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