Maintenance errors, human factors

The application of the science of human factors to eliminating error in all aspects of process design, management, operation, and maintenance is the focus of this work. Human error has been a major cause of almost all of the catastrophic accidents that have occurred in the chemical process industries (CPI). If one adopts the broad view of human error as being the result of a mismatch between human capabilities and process demands, then clearly management s role is critical in the following areas ... 

There is no method of making a plant truly inherently safe, since there is always risk when human activity is involved. But, if we carefully examine the technology available to us, we can make chemical plants inherently safer than they might be without such an examination. We can determine that a plant can be safe, but there are many factors that will determine whether a plant will be safe. CEFIC, the European Council of Chemical Manufacturers Federations (CEFIC, 1986), reports these include human factors that are so difficult to quantify that they are rarely taken into consideration. They include the human side of plant management, operation, and maintenance. Designers cannot do much about these human factors, but they can often do a lot to make the plant easy to operate, and reduce the chances of accidents that may result from human error and mechanical failure. 

Drury, C. G. (1991), Errors in Aviation Maintenance Taxonomy and Control, in Proceedings of the 35th Annual Meeting of the Human Factors Society (San Francisco), pp. 42-46. 

Such a task description invites task analysis, which would lead naturally to human reliability analysis (HRA). Indeed, perhaps the earliest work in this field applied HRA techniques to construct fault trees for aircraft structural inspection (Lock and Strutt 1985). The HRA tradition lists task steps, such as expanded versions of the generic functions above, lists possible errors for each step, then compiles performance shaping factors for each error. Such an approach was tried early in the FAA s human factors initiative (Drury et al. 1990) but was ultimately seen as difficult to use because of the sheer number of possible errors and PSFs. It is occasionally revised, such as in the current FRANCIE project (Haney 1999), using a much expanded framework that incorporates inspection as one of a number of possible maintenance tasks. Other attempts have been made to apply some of the richer human error models (e.g.. Reason 1990 Hollnagel 1997 Rouse 1985) to inspection activities (La-toreUa and Drury 1992 Prabhu and Drury 1992 Latorella and Prabhu 2000) to inspection tasks. These have given a broader understanding of the possible errors but have not helped better define the PoD curve needed to ensure continuing airworthiness of the civil air fleet. 

Errors in this case are taken to include both mistakes and omissions. Vulnerability to systemic errors can be introduced during any part of the life cycle, and its realisation comes into effect during manufacture, installation, maintenance or operation (where the blame is then allocated under the umbrella term of Human Factors). These systematic failures may not all be derivable from assessments such as the FHA or FTA, and many are best identified from service experience. 

Most Human Factors interventions in a Maintenance Organisation can be traced back to the fact that the system was not designed to minimise the possibility of Human Error during maintenance (refer Table 6.1). 

Human factors errors within aviation maintenance industry can be more effectively managed by applying proactive monitoring and early error detecting techniques at both organizational and individual levels ... 

AMMP works in two complementary folds Design and manufacturing as well as workplace and maintainers orientations. Consequently, the process is intended to effectively monitor the seen and/or inherent existence of maintenance human errors causal factors... 

Hall, David. 2005. The role of human factors training and error management in the aviation maintenance safety system. 58th Joint Meeting of the Flight Safety Foundation, 58th Annual IntemationalAir Safety Seminar (IASS). Moscow. November 2005. FSF 245—250. 

This paper deals with the classification of an error type and the characteristics of human errors by each error type for the test and maintenance failures that have led to implanned reactor trips in Korean nuclear power plants. The classification of hmnan errors was basically performed on the taxonomy of Reason s basic error types (Reason 1990). Characteristics of the test and maintenance errors include the major contributing factors or error modes, and predictivity or identifiabil-ity of a potential erroneous action from the viewpoint of a human error prevention or management. 

Human factors. Was the facility hardware designed to minimize human errors in operations and maintenance activities ... 

There are ways to code components so someone does not confuse them. There are ways to design connectors and fittings so only correct mating parts connect. That prevents errors. References listed in the Bibliography provide insight into many techniques for incorporating human factors principles into maintainability. Many maintainability features involve safe maintenance and repair work. 

In Managing Maintenance Error A Practical Guide, James Reason and Alan Hobbs comment appropriately on the need to inquire into the systemic causal factors that shape human error ... 

The application of the science of human factors to eliminating error in all aspects of process design, management, operation, and maintenance is the focus of this work. 

The design also needs to take account of the performance oq>abilities of the operating and maintenance personnel. Attention to human factors will ensure that the installation is tolerant of human errors. Among the appropriate elements in minimizing human error is the systematic application of ergonomic principles to ... 

Use an advanced control room to simplify construction, maintenance and operations. Improved human factors considerations reduce the chance of operator error during an event or accident sequence compared to the large control rooms used in currently operating plants. 

Some of the above items, such as (e), (f), (g) and (h), may not apply to experimental devices. The design shall also take into account the capabilities for performance of the operating and maintenance personnel. Attention to human factors will ensure that the installation is tolerant of human errors. Among the appropriate elements in minimizing human errors are the systematic application of ergonomic principles to the relevant engineered systems the provision of automatic control, protection and alarm systems the elimination of human actions that jeopardize safety the clear presentation of data and reliable communications (see also para. 2.23). 

Dhillon, B.S., Human Reliability, Error, and Human Factors in Engineering Maintenance With Reference to Aviation and Power Generation, CRC Press, Boca Raton, Florida, 2009. 

Dhillon, B. S. 2009. Human reliability, error, and human factors in engineering maintenance. Boca Raton, Fla. CRC Press. 

Close attention to detail is essential in the design of all safety-related control systems, whether they are simple hard-wired systems, or complex systems implemented by software. It is important that safety analysis techniques are used to ensure that the requirements in the specification are met, and that the foreseeable failure modes of the control system do not compromise that specification. Issues of concern, which have been identified, include an over-optimistic dependence on the safety integrity of single channel systems, failure to adequately verify software, and poor consideration of human factors. Good design can also eliminate, or at least reduce, the chance of error on the part of the operator or maintenance technician. ... 

Each of the above examples relate to operational activities rather than maintenance tasks. The reason for this is, quite simply, operational tasks have received more human factors/ergonomics attention than maintenance despite the fact that there is just as much potential for human error in maintenance and maintenance errors can also predispose accidents. 

Discussions with representatives of the participating mining houses (largely based on their fatal risk protocols) together with information from the mining human factors literature were used to identify key aspects of the operation and maintenance of earth-moving equipment were there was a foreseeable risk of human error. 

Jim Reason has written books on absent-mindedness, human error, aviation human factors, managing the risks of organizational accidents and managing maintenance error. Since 2000 his primary focus has been patient safety. Viewed at www.saferhealthcare.org.uk. 

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. 

---