Human error accidents

Among tlie phenomena tliat lead to accidents, human error is tlie most unpredictable. Tliis section describes accidents due to errors of judgment. Even well trained people occasionally make such errors, and one must eitlier accept an occasional mistake or cliange tlie work situation to ininiinize or remove tlie opportunities for error. 

Many human errors occur in labs and cause inaccurate results. Some are careless or irresponsible errors, and some errors are accidents. Human error can ruin the results of ANY test, screening or confirmation GC/MS. 

Coal mine accident human error model construction and team safety management mode analysis... 

ABSTRACT In recent years, coal mine accident happened frequently in our country. Based on the statistics about coal mine accident and accident mechanism analysis, the paper find out the main reason that lead to coal mine accident happened frequently in our country. Based on the existing accident model, it put forward coal mine accident human error model. And make detailed factor analysis and effective analysis for the model. Then, from the angle of team, the paper put forward team safety management mode for coal mine enterprises and the corresponding safety control measures. It is a new safe management thought for China s coal mine industry. 

In summary, the accidents main reason is closely related to human behavior. From macro-viewpoint, if the behaviors of corporate decision-making layer, management layer, operate layer are correct if equipments, machines and tools can achieve inherent safety through the scientific and technical personnel research and safety technical personnel operate standard if environment conforms to safety standards, the accident would not have happened. So, coal mine accidents human error mechanism model is established, human error is the primary reason for coal mine incidents. 

COAL MINE ACCIDENT HUMAN ERROR MODEL... 

By reason analysis for coal mine accident Occurred in our country in recent years, relying on the error theory, based on the accident mechanism that predecessors had established (Li Zhicheng, et al. 2005), the paper constructed coal mine accidents human error model , as shown in Figure 1. 

That the theory coal mine accidents human error model proposed in the paper mainly reflects that human error is the ultimate reason lead to accident. The model contains two parts, that is, inside and out the red line region. Part of outside red line region embodies the relationship from the macroscopic among human error, object misconduct and environmental degradation, and the accident mechanism and consequences Part of inside red region describes the different accident processes from the microscopic. As shown in the model diagram, object misconduct and environmental degradation are... 

Based on the above analysis, the paper give a new definition for accidents category, that is. All coal mine accidents can be divided into 4 categories, that is, accident is directly caused by human error, we called it A class accident accident is caused by human error and object misconduct, we called it B class accident accident is caused by human error and environment degradation, we called it C class accident accident is caused by human error, object misconduct, environment degradation in the same time, we called it D class accident. So, we can say, human error is the ultimate reason of all accidents, and it is the essence of coal mine accident human error model. 

According to the coal mine accident human error model and coal mine accident main reason in our country, the paper raises the method to improve enterprise safety management level by constructing excellent team management mode, shown in Figure 2. 

From the perspective of the coal industry, through making analysis about many coal mine accidents, it established the coal mine accident human error model by observation and interpretation on the coal mine accidents mechanism from a new angle, and provided the reference for coal mine accident prevention business. 

The software life-cycle management should prevent any unverified changes. The possible failures (item 2.) are in principle similar to pre-accident human errors like miscalibration or mispositioning and could be modelled in the same way if not screened out due to low probabihty. This type of failure is clearly CCF suspected. 

Hazardous substances released from plants could cause serious problems to plant employees as well as to the nearby public. The release could be due to accidents (human error), instrument failure, control failure, and natural calamities or through deliberate acts of vandalism, terrorism, or sabotage. The application of inherent security can help in two ways (1) by reducing the likelihood that a facility will be targeted and (2) by minimizing the severity of an incident should an attack occur. Similar to inherent safety principles, one can consider a set of guidelines for inherent security ... 

Various problems involving adjustment of work methods Loss of control of work methods Workplace accidents Human error... 

Human error remains a causal factor in the majority of serious aircraft accidents. Human error causes accidents of fail-safe, fully functional designs. 

ETA breaks down an accident iato its contributing equipment failures and human errors (70). The method therefore is a reverse-thinking technique, ie, the analyst begias with an accident or undesirable event that is to be avoided and identifies the immediate cause of that event. Each of the immediate causes is examined ia turn until the analyst has identified the basic causes of each event. The fault tree is a diagram that displays the logical iaterrelationships between these basic causes and the accident. 

The result of the ETA is a Hst of combiaations of equipment and human failures that ate sufficient to result ia the accident (71). These combiaations of failures are known as minimal cut sets. Each minimal cut set is the smallest set of equipment and human failures that are sufficient to cause the accident if all the failures ia that minimal set exist simultaneously. Thus a minimal cut set is logically equivalent to the undesired accident stated ia terms of equipment failures and human errors. 

For many years the usual procedure in plant design was to identify the hazards, by one of the systematic techniques described later or by waiting until an accident occurred, and then add on protec tive equipment to control future accidents or protect people from their consequences. This protective equipment is often complex and expensive and requires regular testing and maintenance. It often interferes with the smooth operation of the plant and is sometimes bypassed. Gradually the industry came to resize that, whenever possible, one should design user-friendly plants which can withstand human error and equipment failure without serious effects on safety (and output and emciency). When we handle flammable, explosive, toxic, or corrosive materials we can tolerate only very low failure rates, of people and equipment—rates which it may be impossible or impracticable to achieve consistently for long periods of time. 

At one time most accidents were said to be due to human error, and in a sense they all are. If someone—designer, manager, operator, or maintenance worker—had done something differently, the accident would not have occurred. However, to see how managers and supervisors can prevent them, we have to look more closely at what is meant by human error-. 

Frequency Phase 1 Perform Qualitative Study, Typically Using HAZOP, FMEA, or What-if Analysis. To perform a qualitative study you should first (1) define the consequences of interest, (2) identify the initiating events and accident scenarios that could lead to the consequences of interest, and (3) identify the equipment failure modes and human errors that could contribute to the accident... 

A valuable QRA result is the importance of various components, human errors, and accident scenarios contributing to the total risk. The risk importance values highlight the major sources of risk and give the decision maker a clear target(s) for redesign or other loss prevention efforts. For example, two accident scenarios may contribute 90% of the total risk once you realize that, it is obvious that you should first focus... 

Human operator errors are not usually examined in a FMEA, but the effects of human error are indicated by the equipment failure mode. FMEAs rarely investigate damage or injury that could arise if the system or process operated successfully. Because FMEAs focus on single event failures, they are not efficient for identifying an exhaustive list of combinations of equipment failures iliat iead to accidents. 

Human factors, discussed in Section 4.2, enter a fault tree in the same manner as a component failure. The failure of manual actions, that prevent or mitigate an accident, are treated the same as hardware failures. The human error failure probability is conditioned by performance sluiping factors imposed by stress, training and the environment. 

Human errors may be dependent on the specific accident sequence displayed in the event tree, and, for that reason, may be included in the event tree. This requires the human-factors specialist to consider the context of the error in terms of stress, operator training in response to the accident, di.tgnosiic paiierns, environmental, and other performance-shaping factors. 

The event list is not necessarily hardware it may include anything germaine to the accident sequence such as human error. 

Humans control all chemical and nuclear processes, and to some extent all accidents result from human error, if not directly in the accident then in the process design and in the process inadequate design to prevent human error. Some automatic systems such used in nuclear power reactors because the response time required is too short for human decisions. Even in these, human error can contribute to failure by inhibiting the systems. 

In addition to these formal studies of human error in the CPI, almost all the major accident investigations in recent years, for example, Texas City, Piper Alpha, Phillips 66, Feyzin, Mexico City, have shown human error as a significant causal factors in design, operations, maintenance or the management of the process. Figures 4.4-1 and 4.4-2 show the effects of human error on nuclear plant operation. 

Uehara and Hoosegow (1986) Human error accounted for 5S% of the fire accidents in refineries du.j lo improper management 12. improper design 12. improper m,iterials 11 misoperation i improper inspection improper repair 9 - other errors 27%... 

Systematic consideration of human error is neglected because of the belief that computerization of processes will make the human unnecessary. Experience shows numerous accidents in computer controlled plants. Human involvement in critical areas of maintenance and plant modification, continues even in the most automated processes. 

Human error contributed to about 50% of the accident sequences m the RSS but none of the human error data came from the nuclear power industry. Furthermore, very high failure rates 0.5 to 0.1/action) were predicted but are not supported by the plant... 

A critical assembly is a split bed on which fissionable material used to mock up up a separated reactor core that is stacked half on each half. One half is on roller guides so that the two halves may be quickly pulled apart if the neutron multiplication gets too high. Use the Preliminary Hazards Analysis method described in section 3,2.1 to identify the possible accidents that may occur and the qualitative probabilities and consequences. List the initiators in a matrix to systematically investigate the whole process. Don t forget human error. 

This section reflects on the limitations of the PSA process and draws extensively from NUREG-1050. These subjects are discussed as plant modeling and evaluation, data, human errors, accident processes, containment, fission product transport, consequence analysis, external events, and a perspective on the meaning of risk. 

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