Qualitative Prospective Modelling of Human Error : Petroleum Refineries

El presente proyecto pretende validar, en el ámbito de refinación de petróleo, una metodología de análisis de error humano, dando continuidad a la temática desarrollada en los proyectos bienales 2013-15 y 2016-18 empleando la información recabada y los resultados de tales estudios. Asimismo, el tema planteado forma parte del trabajo posdoctoral de la Directora, tomando como base la metodología propuesta en la Tesis Doctoral y aprobada internacionalmente. Para la industria de refinación de petróleo, la seguridad es un aspecto crítico y las consecuencias del accionar humano pueden ser severas, impactando el ambiente, la economía y las personas. Si bien se han establecido normativas y adoptado herramientas de ingeniería para gestionar el riesgo, los errores humanos no son eliminados y los accidentes continúan ocurriendo dado que el análisis de accidentes severos no involucra el análisis de confiabilidad humana. Para dar respuesta a esta problemática, se propone validar un modelo prospectivo cualitativo de error humano en refinerías de petróleo aplicando a accidentes debidamente documentados una metodología que permite identificar qué elementos de la interfaz humano-máquina o de los procedimientos de trabajo van a desviar (o conducir) al operador de la secuencia accidental y, por ende, de la correcta resolución del problema. Así, se podrá determinar si el modelo es lo suficientemente robusto para predecir la secuencia accidental que tuvo lugar. El modelo consta de dos etapas de evaluación: una centrada en el sistema, analizando la secuencia de eventos posibles una vez iniciado el accidente, y la otra, focalizada en el análisis del operario, evaluando su respuesta en función de la información recibida. Como resultado, se podrá identificar los puntos críticos del sistema cuyo diseño, operación y/o mantenimiento requieren modificaciones substanciales; y/o modificar procedimientos de trabajo. Finalmente, compararán los resultados con aquellos obtenidos al aplicar dicho modelo a plantas de biocombustibles.The present project aims to validate, in the field of oil refining, a human error analysis methodology, giving continuity to the theme developed in the biennial projects 2013-15 and 2016-18 using the information collected and the results of such studies. Likewise, the proposed topic is part of the postdoctoral work of the director, based on the methodology proposed in the Doctoral Thesis and approved internationally. For the oil refining industry, safety is a critical aspect and the consequences of human action can be severe, impacting the environment, the economy and people. Although regulations have been established and engineering tools have been adopted to manage risk, human errors are not eliminated and accidents continue to occur since the analysis of severe accidents does not involve the analysis of human reliability. In order to give an answer to this problem, it is proposed to validate a qualitative prospective model of human error in petroleum refineries applying to accidents duly documented a methodology that allows identifying which elements of the human-machine interface or work procedures are going to deviate (or to drive) the operator of the accidental sequence and, therefore, of the correct resolution of the problem. Thus, it will be possible to determine if the model is robust enough to predict the accidental sequence that took place and potential human errors. The model consists of two stages of evaluation: one focused on the system, analyzing the sequence of possible events once the accident began, and the other, focused on the analysis of the operator, evaluating their response based on the information received. As a result, it will be possible to identify the critical points of the system whose design, operation and / or maintenance require substantial modifications; and / or modify work procedures. Finally, the results will be compared with those obtained when applying thed model to biofuel plants

A novel qualitative prospective methodology to assess human error during accident sequences

Numerous theoretical models and techniques to assess human error were developed since the 60's. Most of these models were developed for the nuclear, military, and aviation sectors. These methods have the following weaknesses that limit their use in industry: the lack of analysis of underlying causal cognitive mechanisms, need of retrospective data for implementation, strong dependence on expert judgment, focus on a particular type of error, and/or analysis of operator behaviour and decision-making without considering the role of the system in such decisions. The purpose of the present research is to develop a qualitative prospective methodology that does not depend exclusively on retrospective information, that does not require expert judgment for implementation and that allows predicting potential sequences of accidents before they occur. It has been proposed for new (or existent) small and medium- scale facilities, whose processes are simple. To the best of our knowledge, a methodology that meets these requirements has not been reported in literature thus far. The methodology proposed in this study was applied to the methanol storage area of a biodiesel facility. It could predict potential sequences of accidents, through the analysis of information provided by different system devices and the study of the possible deviations of operators in decision-making. It also enabled the identification of the shortcomings in the human-machine interface and proposed an optimization of the current configuration.Fil: Calvo Olivares, Romina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ingenieria. Instituto de Capacitación Especial y Desarrollo de Ingeniería Asistida por Computadora; ArgentinaFil: Rivera, Selva Soledad. Universidad Nacional de Cuyo. Facultad de Ingenieria. Instituto de Capacitación Especial y Desarrollo de Ingeniería Asistida por Computadora; ArgentinaFil: Núñez Mc Leod, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ingenieria. Instituto de Capacitación Especial y Desarrollo de Ingeniería Asistida por Computadora; Argentin

Latent failures on biodiesel plants

The process to obtain biodiesel is simple, however it is a chemical process in which toxic and flammable substances are used or variables like temperature or pressure should be controlled to avoid any kind of incident. Literature report accidents where most human errors are related to the confidence of operators by this simplicity. Much of these accidents are influenced by a number of factors involved constituting latent failures. This paper presents a summary of latent failures identified on biodiesel plants and a description of their causes and the accepted practices to eliminate them.Fil: Rivera, Selva S.. Universidad Nacional de Cuyo. Facultad de Ingenieria. Instituto de Capacitación Especial y Desarrollo de Ingeniería Asistida Por Computadora; ArgentinaFil: Núñez Mc Leod, Jorge Eduardo. Universidad Nacional de Cuyo. Facultad de Ingenieria. Instituto de Capacitación Especial y Desarrollo de Ingeniería Asistida Por Computadora; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Calvo Olivares, Romina Daniela. Universidad Nacional de Cuyo. Facultad de Ingenieria. Instituto de Capacitación Especial y Desarrollo de Ingeniería Asistida Por Computadora; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza; Argentin

Database for accidents and incidents in the biodiesel industry

The present paper describes the development of an accident and incident database for the Biodiesel Industry for the period 2003-November 2013. The work performed is related to the collection of data from different documental sources and the subsequent setting of a database containing general information about adverse events, its sequence, mitigation, causes, and human, environmental and material consequences occurred in biodiesel facilities during the last ten years. This database came to fill a gap existing in this field. Availability of these data will allow applying risk analysis tools, having a management tool to check organization performance, generating lessons learned to avoid accident recurrence and identifying those accidents more likely to occur. Data statistical analysis shows that the frequency of accidents in biodiesel plants has an increasing tendency, being fires and explosions the main type of accidents that occurred. Inmediate causes and consequences of the accidents have also been analized. Finally, some conclusion are drawn concerning the need of maintaining an update accidental and incidental database and improving biodiesel plants safety based on information obtained.Fil: Calvo Olivares, Romina Daniela. Universidad Nacional de Cuyo. Facultad de Ingenieria. Instituto de Capacitación Especial y Desarrollo de Ingeniería Asistida por Computadora; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Rivera, Selva Soledad. Universidad Nacional de Cuyo. Facultad de Ingenieria. Instituto de Capacitación Especial y Desarrollo de Ingeniería Asistida por Computadora; ArgentinaFil: Núñez Mc Leod, Jorge Eduardo. Universidad Nacional de Cuyo. Facultad de Ingenieria. Instituto de Capacitación Especial y Desarrollo de Ingeniería Asistida por Computadora; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentin

Database for accidents and incidents in the fuel ethanol industry

The purpose of the present research is to collect information about accidents and incidents that have occurred at fuel ethanol facilities from 1998 to October 2014, and to keep complete unified records of them in a database. The developed database contains general information about the accident or incident, its sequence, mitigation measures, its causes and consequences for humans, environment and for the plant. Until now, this information is not available. The work consisted in gathering information from different documental sources and subsequent organization in a database. It complements the previous work made for biodiesel industry and fills the existing gap in the field of ethanol. Knowledge about this information enables us to manage plant risks, since the accidents that are more likely to occur and the main sources of risk can be easily identified. Also, it makes it possible to exchange information with interested third parties. Statistical analysis shows that accident frequency has an oscillatory behavior, rising in the last year. Fire is the most common type of accident, while equipment mechanical failure is the main cause of accident. Partial material loss has been identified as the most common consequence. Finally, some conclusions are obtained concerning to the importance of having an updated and complete accident and incident database.Fil: Calvo Olivares, Romina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ingeniería; ArgentinaFil: Rivera, Selva Soledad. Universidad Nacional de Cuyo. Facultad de Ingeniería; ArgentinaFil: Núñez Mc Leod, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ingeniería; Argentin

Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

Background Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation. Methods WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109. Findings Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0–4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2–6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital. Interpretation In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates

Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

Background: Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation. Methods: WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109. Findings: Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0-4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2-6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital. Interpretation: In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates. Funding: European Society of Intensive Care Medicine, European Respiratory Society