Human Error Severity

Environmental factors such as severe hailstorms and human errors such as impact by aircraft service equipment also cause in-service damage to bonded assemblies. Bonded honeycomb sandwich assemblies are particularly prone to such damage because of their customary use as lightly loaded fairings and flight control surfaces and subsequent thin facesheets and relative fragility. 

After you record the steps of the job, review each step to determine the hazards that exist or that might occur. There are several ways to identify job hazards evaluate the ways human error might contribute to a hazard, record the types of potential incidents and the physical agents involved, and make sure that procedures are clearly written. 

The following are some cases (Oil Insurance Association, 1971) in which human error is involved as one of several errors in a chain. 

This is the tniditional view of human error. There were several retisons w hy ihe mainlenancc pnx o(lurvs were ni i lollowcd ... 

Despite the lack of interest in human factors issues in the CPI in the past, the situation is now changing. In 1985, Trevor Kletz published his landmark book on human error in the CPI An Engineer s View of Human Error (revised in 1991). Several other books by the same author e.g., Kletz (1994b) have also addressed the issue of human factors in case studies. Two other publications have also been concerned specifically with human factors in the process industry Lorenzo (1990) was commissioned by the Chemical Manufacturers Association in the USA, and Mill (1992), published by the U.K. Institution of Chemical Engineers. In 1992, CCPS and other organizations sponsored a conference on Human Factors and Human Reliability in Process Safety (CCPS, 1992c). This was further evidence of the growing interest in the topic within the CPI. 

Measures to reduce human error are often implemented at an existing plant, rather than during the design process. The decision to conduct an evaluation of the factors that can affect error potential at an existing plant may be taken for several reasons. If human errors are giving rise to unacceptable safety, quality or production problems, plant management, with the assistance of the workforce, may wish to carry out a general evaluahon or audit of the plant in order to identify the direct causes of these problems. 

In addition to the proactive uses of the SRK model described in the two previous sections, it can also be employed retrospectively as a means of identifying the underlying causes of incidents attributed to human error. This is a particularly useful application, since causal analyses can be used to identify recurrent vmderlying problems which may be responsible for errors which at a surface level are very different. It has already been indicated in Section 2.4.1 that the same observable error can arise from a variety of alternative causes. In this section it will be shown how several of the concepts discussed up to this point can be combined to provide a powerful analytical framework that can be used to identify the root causes of incidents. 

Several examples have already been provided of the use of cognitive models of error to evaluate the possible causes of accidents that have already occurred. This form of retrospective analysis performs a vital role in providing information on the recurring underlying causes of accidents in which human error is implicated. The advantage of an analytical framework driven by a model of human error is that it specifies the nature of the questions that need... 

The overall conclusion that can be drawn from a survey of CPI data collection systems is that the better systems do attempt to address the causes of human error. However, because of the lack of knowledge about the factors which influence errors, the causal information that is collected may not be very useful in developing remedial strategies. General information in areas such as severity, work control aspects and the technical details of the incident will be required in all data collection systems. However, in almost all cases a structured process for causal analysis is lacking. Some of the requirements for causal analysis are set out in the following sections. 

Human error tmalysis (HEA) is a systematic evaluation of the factors tliat influence tlie performance of human operators, maintenance staff, teclmicians, and otlier persomiel in tlie plant. HEA involves the evaluation of one of several types of task analysis, which is a metliod for describing tlie physical and enviromiiental characteristics of a task along witli tlie skills, knowledge, and capabilities required of tliose who perform the task. Tliis type of analysis can identify error-likely situations tliat can cause or lead to an accident. 

Piping failure can be caused in several ways. A study by U.S. EPA16 has shown that piping failure accounted for a substantial portion of releases at USTs. Spills and overfills are usually caused by human error. Repeated spill can also increase the corrosive nature of soils. 

Several qualitative approaches can be used to identify hazardous reaction scenarios, including process hazard analysis, checklists, chemical interaction matrices, and an experience-based review. CCPS (1995a p. 176) describes nine hazard evaluation procedures that can be used to identify hazardous reaction scenarios-checklists, Dow fire and explosion indices, preliminary hazard analysis, what-if analysis, failure modes and effects analysis (FMEA), HAZOP study, fault tree analysis, human error analysis, and quantitative risk analysis. 

There are several approaches to cleaning. The favored approach is clean-in-place (CIP), in which cleaning solutions are piped to the vessel under computer control. In cases where CIP is not suitable, clean-out-of-place (COP) is used. This approach is mostly for smaller items. COP may be carried out manually or with automated tanks. A third approach is manual cleaning, although this is prone to human error and is not generally adopted. 

When you find a human error event, the type of gate is not particularly important, because while several factors may have combined to cause the error, a different person may have made the same error with only one factor present. 

Assured safety with features that minimize the negative consequences of human error, especially a reduction in the chance of occurrence of severe core damage by at least a factor of 10 less than former, contemporary designs,... 

Another advanced and novel sample preparation technique is online solid phase extraction (online SPE). Although the extraction mechanism is as the same as traditional offline SPE, online SPE offers several advantages. Because sample preparation is carried out during analysis, it eliminates the time needed for sample preparation thus increases throughput significantly. Additionally, because the entire sample is eluted to the LC-MS/MS system, it may increase assay sensitivity. Finally, because there is no manual extraction involved, it may reduce human error, potential contamination, and inconsistent recovery. 

Another important benefit of implementing an advaneed control system is the reduction in maintenance requirements and decrease in unexpected failures. Despite the advanced state of automation technologies and/or diagnosis technologies, the most important automation parameter is the reliability of each component. In the case of 300-mm fab, minimal direct human intervention is required. An advantage of this mode of operation is the elimination of failure caused by accidental human errors. The disadvantage on the contrary is that there is no scope for any human intervention to correct any failures immediately or reduce the severity of the failure. Therefore, the overall... 

The risk assessment process can be conducted by examining record types to see if they are GxP or non-GxP, and then applying severity checks, likelihood, and probability of detection criteria, as illustrated in Figure 15.2. The most severe scenarios shonld be linked to direct patient/consnmer impact. GxP noncompliance and broken license conditions are severe in their own right bnt not as critical as patient/consumer health in this analysis." Its likelihood will be influenced by the degree of human error in how the record is input and used. The probability of detection needs to take into account the probability of the impacted record being used. Once failure modes are understood, then the appropriate design controls can be introduced. These should be documented and validated as part of the computer system life cycle discussed earher in this book. 

From the studies conducted by this committee in the past several years, it can be concluded that the quality of peptides produced by ABRF member laboratories is high, as judged by modem analytical techniques. However, there have always been a few less than satisfactory samples for which the source of synthetic problems could only be attributed to human error. In the present study, errors of this type originated not only from some member laboratories, but from manufacturers, as illustrated in some of the examples described below. 

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