Error management results

There is no doubt that this approach to error management resulted in significant enhancements to safety. However, this approach failed to emphasize the inevitability of error and its spontaneous occurrence even within the best-designed systems. The next step was developing an approach that accepted both the ubiquity and inevitability of human error and therefore focnssed not only on error reduction, but also on the subsequent management of error to either mitigate or ameliorate any effects of error on system performance. 

To be able to systematically identify opportunities for reducing human error, it is useful to ask the question, What is human error One definition is that human error is an inappropriate or undesirable human decision or behavior that reduces, or has the potential for reducing safety or system performance (Rasmusssen 1979). There is a tendency to view errors as operator errors. However, the error may result from inadequate management, design, or maintenance of the system. This broader view which encompasses the whole system can help provide opportunities for instituting measures to reduce the likelihood of errors. 

Assume that the system described below exists in a process unit recently purchased by your company. As the manager, the safety of this unit is now your responsibility. You are concerned because your process hazard analysis team identified the potential for an operator error to result in a rupture of the propane condenser. You have commissioned a human reliability analysis (HRA) to estimate the likelihood of the condenser rupturing as the result of such an error and to identify ways to reduce the expected frequency of such ruptures... 

A lot of the time, when you re conducting an experiment, you will run it more than once, especially if it is inexpensive. Scientists run experiments more than once so that the random errors that result from taking measurements, such as having to guess a length between two hash marks on a ruler, cancel themselves out and leave them with a more precise measurement. However, the question remains how should you consolidate all of the data into something that s more managable to use ... 

There are a number of cases on the Unfair Contract Terms Act and on the requirement of reasonableness. The cases must, however, be treated with caution for the decision in each turns on its facts and just because one case is decided one way it does not mean that all others will follow. One example is St Albans City and District Council v International Computers Ltd [1996] 4 All ER 481. The facts were that the council had ordered a computer system from ICL to enable them to compute the Community Charge for the forthcoming year. ICL insisted on using its standard terms and conditions which stated that its liability will not exceed the price or charge payable for the item of Equipment, Program or Service in respect of which liability arises or 100,000 (whichever is the lesser)... . Errors in the software and incorrect advice from ICL s project manager resulted in an overestimate of the population of the area, an undercharge of residents and a loss to the council of 1.3 million. 

This study has provided a detailed account of error management, through the analysis of experts imderstanding of error avoidance, detechon and resolution. From the results of this study, it is evident that elements of error management share much in conunon with our current understanding of Crew Resource Management (CRM). 

The worst error management can make is to become so engrossed in the process of managing that it mistakes the process itself for results. Results are achieved only when customers buy your products at a price that makes a profit for your firm. 

Rationale. Few would argue that an effective and widespread learning process is essential to ensure that error management within safety-critical systems is continually informed and improved. Including the results of such lessons in training programmes, safety review bulletin, etc., will raise staff awareness levels. 

RISKMAN includes extensive error checking and configuration management fin c uality eontn 1. Key module elements and intermediate results are time and date stamped keystrokev of modifications leave an audit trail. 

Error conditions at various levels of the organization result from inappropriate policies, or ineffective implementation of good policies by line management. Poor practices may produce "latent failures" that are not actuated until in combination with other conditions or failure that produce an accident. 

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 ... 

Inspection of the HRA event tree reveals that the dominant human error is Error A the operator failing to isolate the propane valves first. The other potential human errors are factors only if a propane isolation valve sticks open. Based on these qualitative results alone, a manager rrught decide to periodically train operators on the proper procedure for isolating a failed condenser and to ensure that operators are aware of the potential hazards. The manager might... 

This manager requested quantitative results, so the analyst must estimate the probability of each failure or error included in the event tree. Data for all the failures and errors in this particular problem are available in tables in the Handbook, Swain and Guttman (1983). The analyst must modify these data as necessary to account for specific characteristics of the work situation, such as stress levels, equipment design features, and interoperator dependencies. Table 5.1 summarizes the data used in this problem. 

Human error Physical and cognitive actions by designers, operators, or managers that may contribute to or result in undesired events. 

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