Root cause development

Hazard Evaluation Hazard, Plant, Process, Equipment, Process Variables, Position, Cause, Consequence, Initial-Event (Root Cause) Develop/generate by safety experts/engineers/auditors Follow-up and monitor by CAPE-SAFE and safety experts/engineers/auditors... 

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. 

The method is well-structured and provides clear, standardized procedures on how to conduct an investigation and represent the incident process. Also it is relatively easy to learn and does not require the analyst to have a detailed knowledge of the system under investigation. However, the method alone does not aid the analyst in identifying root causes of the incident, but rather emphasizes the identification of the propagation of event sequences. This is an important aspect of developing a preventive strategy. 

In general, the value of a psychological perspective in incident analysis is that it directs the analyst to search for causes that would not otherwise have been considered. This means that the development of preventative strategies will be better informed. In addition, an evaluation of causes from a psychological perspective can be useful when the "root cause" appears to be an otherwise incomprehensible failure on the part of an individual. A psychological analysis can break the "causal log jam" by providing an explanation. 

This case study concerns the events leading up to the hydrocarbon explosion which was the starting point for the Piper Alpha offshore disaster. It describes the investigation of the incident using the sequentially timed events plotting (STEP) technique. Based on the STEP work sheet developed, the critical events involved in the incident are identified and analyzed in order to identify their root causes. 

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. 

This case study illustrates how the methodologies described in Chapter 6 can be used to analyze plant incidents and identify the root causes of the problems. Based on this information, specific error reduction strategies can be developed to prevent similar incidents from occurring in the future. Also, the findings of such an analysis can provide the basis for more general discussions about the prevalence of similar error inducing conditions in other plant areas. 

Development of reactive programs including data collection and root cause analysis systems... 

For example, if tube failure occurs due to caustic gouging corrosion, the root causes are most likely related to the effects resulting from the availability offree sodium hydroxide in the BW, coupled with the development of localized caustic concentration. Control generally requires a twofold approach to remove the causes of this particular problem ... 

An EPA-OSHA accident investigation at Napp Technologies Inc. in Lodi, New Jersey, developed the root causes and recommendations to address the root causes. Describe the accident, and develop layered recommendations for this specific accident. See http // www.epa.gov/ceppo/pubs/lodiintr.htm. 

The answer to the second question was obtained by using models from organizational control theory. A deviation can re-occur due to ineffective operation of the organization s control process. A theoretical model of this control process, in which causes of precursors can be expressed in terms of ineffective control elements of the organization s control process, was derived from existing models in literature. However, as safety literature shows, there are certain conditions shaping a situation that make these control elements ineffective. These conditions, sometimes called latent conditions in safety literature are the actual root causes of precursors and possible accidents. In this thesis a classification has been developed which identifies six main types of latent conditions (these six latent conditions are context related but... 

Root cause Primary reason why an incident occurred, developed through systematic analyses. 

With the plant interview information, verification of the data, and the completion of the simple calculations, an experienced troubleshooter will develop a set of hypotheses for the root cause of the defect. After the hypotheses are established, a series of experiments need to be developed that accept or reject the hypotheses. Once a hypothesis is accepted via experimentation, then the next step is to develop a technical solution to remove the defect. Often more than one technical solution Is possible. The best technical solution will depend on the cost and time to implement the solution, machine owner acceptance, and the risk associated with the modified process. An accepted hypothesis must drive the technical solution. If a hypothesis is not accepted prior to developing a technical solution, then the troubleshooter may be working on the wrong problem and the defect may not be eliminated from the process. 

This example clearly shows that developing and accepting a hypothesis based on accurate and complete information is necessary for setting an acceptable technical solution. If the plant manager could have persuaded the resin manufacturer to develop a new resin that was similar to the incumbent resin, then the defect would still be there, the cost of the troubleshooting process would have been extremely high, the supplier would have incurred unnecessary development costs, and a high level of defective parts would still have occurred because the root cause would not have been removed. 

This case study was developed with an alternative hypothesis and then a second hypothesis, and the experiments were designed properly to determine quickly the root cause of the defect in the part profile. If the hypotheses and experiments had not been developed properly, the time required to troubleshoot the problem would have increased or the project would have failed. 

Due to the high cost of replacing the feed casing and the lack of direct evidence that the ledge and large flight clearance were the root cause of the reduced rate, an alternative experiment needed to be developed that simulated the process. Without these data plant personnel were unwilling to replace expensive components and incur downtime based on indirect evidence. 

---