Contributing factors and root causes

The MORT system uses the term root cause in the sense of the most basic cause of an accident or incident (Cornelison, 1989). It can be traced back to a lack of adequate management control that results in substandard practices and conditions and subsequently in an accident. 

In the research literature we find many different checklists of causal factors. Such checklists are used in accident investigations for the purpose of ensuring that all relevant causal factors are identified. They are also used in the coding of causal factors as input to accident statistics. These statistics are in turn used in identifications of common causal factors, which are focused on action plans to improve safety. 

Level ILCI model (Bird SMORT (Kjellen MORT-based TRIPOD (Reason, 1991) 

General and SHE Lack of control Higher management Policy and implementation Source failure types 

Functional department Immediate causes Daily operation Specific factors General failure types 

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The input to the accident process consists of contributing factors and root causes. Contributing factors are more stable conditions at the workplace. By changing such factors, more lasting effects will be achieved. In practice, it is sometimes difficult to separate contributing factors (input) and deviations in the accident sequence (process). 

We will later apply the accident-analysis framework in a review of different types of methods used in the collection and analysis of data of accident risks. We will start at the output side of the model by reviewing the different types of classification systems used to document the consequences of accidents and different measures of loss. We will then continue by looking into the classification systems used to document incidents and deviations. Finally, we will review the different classification systems for contributing factors and root causes. Our aims will be twofold first, to be complete, i.e. by presenting all alternative means of measuring and classification, and second, to give specific advice on the preferred method. The reader will find recommended alternatives in shaded tables and checklists. 

Figure 6.4 Hierarchical relation between contributing factors and root causes (input).

The interviews should start as soon as possible after the event and initially focus on the immediate sequence of events associated with the accident or near accident and the emergency response. Initially, the interviewee is asked to give a narrative of the event from his or her perspective. The interview is then used to examine detailed facts and to confirm earlier received information. First, participants and witnesses are interviewed in order to establish an accurate description of the sequence of events. Next, the line organisation and staff officers are interviewed to identify contributing factors and root causes. 

Conclusions, i.e. the commission s judgements regarding contributing factors and root causes of the accident. 

We now move further to the left in the accident-analysis framework (Figure 16.1). We will look into SHE performance indicators based on information about contributing factors and root causes. The organisation and SHE management system are in focus. These indicators have many similarities to the audit methods described in Section 14.2. 

Accidents and near accidents are unwanted events occurring at random points in time. At the same time, they represent opportunities of learning about hazards and causal factors at the workplace and in the company. We should grab the opportunities when they occur and conduct adequate investigations. Workplace inspections and SHE audits are pre-planned activities that also represent opportunities of learning. They focus on deviations, contributing factors and root causes and not, in the first place, on hazards. 

If yes, for each incident, attach the incident report or give the following information Description of the incident, chronology of verifiable events, other pertinent facts, root causes and contributing factors, and proposals for corrective action. 

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. 

The report presents the findings from the analysis of the RCP failures. Estimates of the annual frequency for the spectrum of leak rates induced by RCP seal failures and their impact on plant safety (contribution to coremelt frequency) are made. The safety impact of smaller RCP seal leaks was assessed qualitatively, whereas for leaks above the normal makeup capacity, formal PRA methodologies were applied. Also included are the life distribution of RCP seals and the conditional leak rate distributions, given a RCP seal failure the contribution of various root causes and estimates for the dependency factors and the failure intensity for the different combinations of pump designers and plant vendors. 

Inefficiency in the presentation of human error root-causes. The identification and presentation of the root-causes of human errors would considerably improve HRA, because it would allow deeper understanding of the error-making process, more accurate quantification of the contributing factors, and less subjectivity in the analysis. The difficulties in the systematic and clear mapping of the cause-and-effect relations between technological, human and environmental factors in an error-making process has resulted to their partial inclusion in current HRA methods. 

This theory promotes the idea that accidents result from various hazards or other factors interacting in some manner. Accident prevention professionals use different terms to describe these factors. Some refer to the factors as primary and secondary causes, whereas others use terms such as immediate and contributing causes, surface and root causes, or causes and subcauses. Most investigators agree that accidents happen due to multiple and sometimes complex causal factors. 

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. 

Thorough documentation of medication errors provides information about the severity of the error as it relates to the effeet on the patient, the product(s) involved, the competence of staff handling the produet or proeessing the order, any contributing factors that may predispose a product to misuse, and the suspected root cause of the error. USP adds certain codes to MER Program data in order to characterize the error as it was reported. These codes include the type of error and the possible eause(s) of error. The following list shows some of the produet eharaeteristics that have been recorded over 9 years to have caused or eontributed to a medication error. 

A few of the prominent root causes and contributing factors that were identified include ... 

Cause analysis is usually divided into three types (1) direct causes (2) contributing causes and (3) root causes. The direct cause of an incident is the immediate event or condition that caused the incident. Contributing causes are events or conditions that collectively increase the likelihood of the direct cause but that are not the main factors causing the incident. Root causes are the events or conditions underlying the root cause. Corrective measures for root causes will prevent the recurrence of the incident. In simple cases, root causes include materials or equipment deficiencies or their inappropriate handling. More complex examples are management failures, inadequate competencies, omissions, nonadherence to procedures, and inadequate communication. Root causes can be typically attributed to an action or lack of action by a group or individual. 

It is essential to identify the cause of packaging failure such as vehicle collision, improper loading, or corrosion. It is important to realize the difference between the contents of a package involved in an incident and the root cause of an incident. Corrosive materials were the contents of 35.7% of 1998 incidents and the root cause of an incident. Corrosion was implicated as a contributing factor in 1.35% of the total incidents in 1998 (24). A total of 79 (38.3%) of the 206 corrosion-related incidents... 

Root cause analysis is a most important technique that can be used in determining the direct cause and contributing factors for the mishap. Succinctly, the technique asks successive questions of why did this event happen until no further response is available and the root cause should be identified. 

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