A systems perspective of managing error recovery and tactical re-planning of operating teams in safety critical domains

Introduction

Research in human error has provided useful tools for designing procedures, training, and intelligent interfaces that trap errors at an early stage. However, this “error prevention” policy may not be entirely successful because human errors will inevitably occur. This requires that the error management process (e.g., detection, diagnosis and correction) must also be supported. Research has focused almost exclusively on error detection; little is known about error recovery, especially in the context of safety critical systems. The aim of this paper is to develop a research framework that integrates error recovery strategies employed by experienced practitioners in handling their own errors.

Method and Results

A control theoretic model of human performance was used to integrate error recovery strategies assembled from reviews of the literature, analyses of near misses from aviation and command & control domains, and observations of abnormal situations training at air traffic control facilities. The method of system dynamics has been used to analyze and compare error recovery strategies in terms of patterns of interaction, system affordances, and types of recovery plans. System dynamics offer a promising basis for studying the nature of error recovery management in the context of team interactions and system characteristics.

Impact on industry

The proposed taxonomy of error recovery strategies can help human factors and safety experts to develop resilient system designs and training solutions for managing human errors in unforeseen situations; it may also help incident investigators to explore why people's actions and assessments were not corrected at the time.     

浅析如何制定企业职业安全健康方针

制定适合企业自身发展的职业安全健康方针至关重要,然而目前这方面的研究相对较少。本文收集了国内27家、国外10家知名企业的职业安全健康方针,统计分析了国内外职业安全健康方针在形式和内容上的区别与联系。通过定性分析和定量研究,得出国外企业职业安全健康方针的共性特点和国内企业职业安全健康方针的最常见组合模式。理论联系实际,将我国《职业安全健康管理体系规范（》GB/T28001-2004）中方针的编写要求与研究结论相结合,探讨在新形势下,如何制定企业职业安全健康方针的方法。     

An evaluation approach using a HARA and FMEDA for the hardware SIL

Safety instrumented systems (SIS) are becoming increasingly complex, and form a growing proportion of programmable electronic parts. The IEC 61508 global standard was established to ensure the functional safety of SIS; however, it was expressed in highly macroscopic terms. The safety integrity level (SIL) is a criterion describing whether a component meets the safety requirements of a SIS. The safety requirements give a target SIL for the expected risks using hazard analysis and risk assessment (HARA). The SIL must correspond to the safety requirements. This study introduces an evaluation process for determining the hardware SIL through failure modes, effects, and diagnostic analysis (FMEDA). First, the components of the SIS subsystem are defined in terms of failure modes and effects, and then the failure rate and failure mechanism distribution are assigned to each component. The safety mode and detectability of each failure mode are determined for each component and, finally, the hardware SIL is evaluated. We perform a case study to evaluate the hardware SIL of the flame scanner system using HARA and FMEDA, where the safety requirement of the flame scanner was determined using the risk graph method. We verified that the hardware SIL of the flame scanner corresponded to the safety requirement.     

Fire and Explosion Index calculation method incorporating classified safety measure credits

Based on an analysis of two methods for the modification of the F&EI for the DOW Guide, it is found that the effects of safety measures are not classified. Moreover, the efficiency of the measures is magnified to various degrees, as the positive impact of the loss reduction measures are applied to the rate reduction of the intrinsic hazard in the evaluated unit. For this reason, a modification method using classified safety measures is proposed, in which safety measures are classified into process protection measures and loss reduction measures. The calculation of the modified F&EI involves the credit factors of process protection measures, whereas the determination of the maximum probable property damage incorporates the loss reduction measures. This method could provide more reasonable reference data for hazard units because of its more objective and reasonable evaluation results.     

Human factors applied to alarm panel modernization of nuclear control room

Human factors deal with issues related to humans, their behavior and the physical aspect of the environment in which they work. A control room is a complex system where operators perform plant operation using control systems and carry out monitoring and administrative responsibilities. For safe operation of industrial installation, the performance of the control room crew plays an important role. In this respect, a well designed control room is crucial for safe and efficient operation. The aim of this paper is to propose a methodological framework applied to nuclear control room evaluation, through participatory ergonomics, using operator activity analysis and human factors questionnaire as aid tools. We describe a case study in which the methodology framework was used in the evaluation process of a nuclear control room. The information gathered made possible a series of recommendation for the adequacy of the control room design, assisting in the safety assessment of the nuclear plant operation and justifying the alarm panel modernization.     

Small Business Owners’ Knowledge of Their Occupational Health and Safety (OHS) Legislative Responsibilities

This article reports the results of a study investigating the nature and extent of small manufacturing business owners’ knowledge of Occupational Health and Safety (OHS) issues. Interviews were conducted with 33 owners of small manufacturing businesses in Sydney, Australia. Results showed that whereas the majority of owners had basic awareness of the existence of OHS legislation, they were often unaware about the extent of their legal OHS responsibilities. Owners were found to have minimal OHS training and practical OHS expertise. Lack of appropriate industry specific OHS information was found to be a major factor that inhibited the owners’ ability to deal with OHS issues effectively.     

金属压力容器水压试验声发射检测

通过对容积为504．94m3的某型号压力容器出厂前水压试验的声发射检测,分析了其在升压和保压过程中的声发射信号特征及其来源。结合AE信号参数、波形及定位图分析,对该容器进行了声发射活性评价,确定需要后续复检的强活性区域。文章为压力容器的声发射检测和安全评价提供了理论指导和参考数据。     

关于人机系统安全分析中人的因素的一些探讨

在对人机系统安全分析中，重点对人的因素进行探讨，并提出了新的见解。在人机系统中，人的生理特性和心理特性不是恒定不变的，特别在人机系统安全分析与设计时，关于人的因素必须从动态特性变化来认识     

浅谈安全工程专业学历教育

从安全工程师应具备的知识结构出发，主要讨论了安全工程专业学历教育中的课程设置及办学过程中存在的一些的问题。     

A posteriori hazard analysis and feedback information of an accidental event in the grains storage of an agrochemical product

The present study concerns a hazardous event which occurred in an industrial storage tank of a ground insecticide. A preliminary post-accident approach of the hazard evaluation is performed. The rapid report of the presence of an unstable functional group in the active product and of its potential thermal instability (CHETAH indices) has led to complete this examination by an experimental study of thermal analysis using isotherm exposition measurement (DTA) or with temperature programming by differential scanning calorimetry (DSC) and oxidability tests (BAM). The apparent kinetics of decomposition of the active matter of the ground insecticide has been represented by a global Arrhenius law.

A model designed for the simulation of heterogeneous thermal runaways based on the numerical solution of the transient mass and energy balances has been further applied to define the critical conditions of the storage and simulate its behavior.

The results obtained during this analysis with the experienced feedback allowed us on one side to explain the hazardous event and especially on the other side to modify the operating protocol of the conditions of formulation of the active matter on the inert mineral support.