General failure types

HFAM has 20 groups of factors instead of the 10 general failure types of the TRIPOD approach. The reason for this is that all of the 10 TRIPOD GFTs would be applied in all situations, even though the actual questions that make up the factors may vary. In the case of HFAM, it would be rare to apply all of the factors unless an entire plant was being evaluated. HFAM uses a screening process to first identify the major areas vulnerable to human error. The generic factors and appropriate job specific factors are then applied to these areas. For example, control room questions would not be applied to maintenance jobs. 

Another link exists between the PIF concept and the sociotechnical assessment methods described in Section 2.7 The checklists used in the TRIPOD methodology are essentially binary questions which evaluate whether the sets of PIFs making up each of the general failure types are adequate or not. The hierarchical sets of factors in HRAM are essentially PIFs which are expressed at increasingly finer levels of definition, as required by the analyst. The audit tool which forms MANAGER also comprises items which can be regarded as PIFs which assess both management level and direct PIFs such as procedures. 

Tripod Delta An integrated system of safety management which assesses general failure types, such as maintenance and design problems, and their potential impact on safety. 

Functional department Immediate causes Daily operation Specific factors General failure types... 

In the TRIPOD model, the underlying factors at the workplace or department level behind accidents are called latent failures. Based on research into accident causation, 11 different so-called General Failure Types have been identified (Wagenaar in Feyer and Williamson, 1998). They comprise... 

Tripod Delta is a SHE performance profile developed for Shell (Van der Want, 1997). Based on the Tripod accident model presented in Sections 5.2, eleven so-called general failure types were identified. Eight of these focus on conditions at the workplace, ordered in relation of their proximity to the victim ... 

The remaining three general failure types concern the general and SHE management system and include ... 

The absence or presence of each of the eleven general failure types is determined through the employment of indicator questions, which are administered through a questionnaire to the workforce. There are about 2200 such questions. Each time a questionnaire is distributed at a plant, a random selection of 10 per cent of the questions covering all general failure types are selected and adapted to the conditions at the plant. The results are used to compute a so-called failure-state profile. Eigure 19.1 shows an example. 

In addition to identifying general failure modes that are common to many types of machine-train components, failure-mode analysis can be used to identify failure modes for specific components in a machine-train. However, care must be exercised when analyzing vibration profiles, because the data may reflect induced... 

In general three types of dependent failures are distinguished ... 

Besides the average level at which failures occur in the falling weight impact test, the type of failure can also be of importance in judging the relative impact performance of a material in practice. There are generally three types of failure ... 

In general, these types of failures result in risk to in-plant personnel. However, vessel fragments can be accelerated to significant distances. The Canvcy Study (Health Safety Executive, 1978) considered projectile damage effects on other process vessels. 

The input information of net a is the key voltage data of the circuit. Sometimes, for a better effect of classification the data ought to be processed in advance such as filtered or uniformized when necessary. As usual, the output of net a is the codes of failure modes, which indicate where the faults locate. Generally a code usually represents several failure modes, for the reason that there are always some failure types causing the same voltage change. 

Failure types are general classes of organisational and management failures. There are two failure types ... 

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

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