o desafiodos fatoreshumanos · 2017-11-23 · seveso_30anos - opcao2 author: goncalo.sousa created...

30 ANOS de SEVESO em PORTUGAL

O desafio dos fatores humanos

2017

AGENDA

1. Significado de “Fatores Humanos”

2. Taxonomia da falha humana

3. O erro humano no acidente de Texas City

4. SCTA - Safety Critical Task Analysis

5. Conclusão

Desafio dos fatores humanos | 2017

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Significado de “Fatores Humanos”

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Significado de Fatores Humanos

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HSE

Desafio dos fatores humanos| 2017

• “Everyone can make errors no matter how well trained and motivatedthey are. Sometimes we are set up by the system to fail. Thechallenge is to develop error-tolerant systems and to prevent errorsfrom occurring” (HSE, 1999).

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VIDEO


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Definição


“making it easy for Homer to do the right thing”


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Definição


• Os Fatores Humanos devem dar resposta:

• O trabalho e as suas características;

• As pessoas e a sua competência;

• A organização e os seus atributos.

• Alguns exemplos de fatores relacionados com o Trabalho, Pessoas e a Organização, frequentementedesignados como Performance Influencing Factors (PIF), não são mais do que o contexto no qual ocomportamento acontece.

• Link para os PIF:

Os FATORES HUMANOS relacionam-se com o assegurar o correto alinhamento entre as Pessoas, o

Equipamento que usam, a Atividade que conduzem e o Ambiente no qual trabalham.

Taxonomia da falha humana

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O DESAFIO DOS FATORES HUMANOS9

Taxonomia da falha humana


O erro humano no acidente de Texas City

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O ERRO HUMANO NO ACIDENTE DE TEXAS CITYMogford and CSB Reports



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O ERRO HUMANO NO ACIDENTE DE TEXAS CITY

Competência

Procedimentos

Cultura

Investigações e aprendizagem

Comunicações

Supervisão

Alarmes

Interfaces

Staffing levels

Gestão da fadiga

Mudançaorganizacional

Liderança

Mogford and CSB Reports

SCTA - Safety Critical Task Analysis

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SCTA - Safety Critical Task Analysis

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O que é?


• TA (análise da tarefa): o estudo do que é requerido, em termos das ações e do processo mental associado, por forma a atingir um determinado objetivo.

• SCTA: alarga o conceito anterior a um processo no qual o impacto dos fatores humanos comoelemento potenciador da ocorrência de acidentes graves pode ser avaliado.• Deverão ser incluídos na análise eventos iniciadores, prevenção e deteção, controlo e mitigação e resposta à

emergência

O processo de SCTA deve ser interpretado como incluindo:• Determinação de quais as tarefas críticas;

• Compreensão sobre qual a ação (ou inação) humana que pode conduzir a uma falha mais severa ou de maiorprobabilidade;

• Recomendações sobre como identificar e instalar barreiras de Proteção adequadas, por forma a reduzir a probabilidade e as consequências da falha humana.

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SCTA - Safety Critical Task AnalysisMetodologia

16SCTA – Safety Critical Task AnalysisHTA – Hierarchical task analysis

Conclusão

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VIDEO

Conclusão

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O Desafio


Piper Alpha, Texas City, Buncefield e Macondo são incidentes queassociaram a falha humana e técnica. Enquanto avanços significativosforam obtidos na parte técnica e de Engenharia de Segurança deProcesso, o facto é que não conseguiremos prevenir a ocorrência defuturos acidentes graves se não considerarmos também a falhahumana e os aspetos organizacionais associados.

OBRIGADO

e

“Don’t forget to BE AFRAID”

[email protected]

Desafio dos fatores humanos | 2017

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Are you inclined to think about what could go wrong?

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Fatores HumanosCompetence

• “Inadequate training for operations personnel, particularly for the board operator position, contributed to causing the incident. The hazards of unit startup, including tower overfill scenarios, were not adequately covered in operator training” (CSB, 2007, p.91).

• “The hazards of unit startup were inadequately covered in operator training and did not prepare the Board Operator for the tasks he was responsible for on the day of the incident. This insufficient training was compounded by the lack of annual performance appraisals, individual skill development plans, and abnormal situation management simulator training. BP provided only basic general training to its operators” (CSB, 2007, 294).

Voltar

Desafios dos fatores humanos| 2017

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Fatores HumanosProcedure

• “The ISOM raffinate section startup procedure lacked sufficient instructions for the Board Operator to safely and successfully start up the unit” (CSB, 2007, p.75).

• “These deviations were not unique actions committed by an incompetent crew, but were actions operators, as a result of established work practices, frequently took to protect unit equipment and complete the startup in a timely and efficient manner” (CSB, 2007).

Voltar


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Fatores HumanosCulture

• “The BP Texas City tragedy is an accident with organizational causes embedded in the refinery’s culture” (CSB, 2007, p.175).

• “The disaster at Texas City had organizational causes, which extended beyond the ISOM unit, embedded in the BP refinery’s history and culture” (CSB, 2007, p.139).

• “A workplace environment characterized by poor motivation, unclear expectations around supervisory /management behaviors, no clear system of reward and consequences, and high distrust between leadership and the workforce, had developed over a number years within the site” (Mogford Report, 2005, p.153).

Voltar


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Fatores HumanosInvestigation and Learning

• “BP had not implemented an effective incident investigation management system to capture appropriate lessons learned and implement needed changes. Such a system ensures that incidents are recorded in a centralized record keeping system and are available for other safety management system activities such as incident trending and process hazard analysis” (CSB, 2007, p.100).

• “Many of the safety problems that led to the March 23, 2005, disaster were recurring problems that had been previously identified in audits and investigations” (CSB, 2007, p.138).

Voltar


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Fatores HumanosCommunications

• “BP had no policy for effective shift communication, nor did it enforce formal shift turnover or require logbook/procedural records to ensure communication was clearly and appropriately disseminated among operating crews” (CSB 2007, p.77).

Voltar


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Fatores HumanosSupervision

• “There was little investment in supervisory/management training, and an absence of role models within supervision, and, as a result, supervisory /management behaviors were inadequate. There were no clearly documented expectations for supervisors’ roles, including those stepping up to an acting supervisory role” (Mogford Report, 2005, p.153).

Voltar


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Fatores HumanosAlarms

• “ISOM operations personnel experienced a ‘flood’ of alarms (hundreds of alarms registering in a short period) and weren’t able to assess the situation or warn others prior to the explosion.” (Human Factors 101).

Voltar


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Fatores HumanosInterfaces

• “Not only was there malfunctioning instrumentation and incorrectly calibrated instrumentation during the startup; a poorly-designed interface made it difficult to determine that the tower was overfilling. Panel operators didn’t have visibility of actual process conditions.” (Human Factors 101).

• “Different control screens showed how much liquid raffinate was entering the unit and how much raffinate product was leaving the unit; making it less clear that there was an imbalance between the two readings.” (Human Factors 101).

Voltar


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Fatores HumanosStaffing levels

• “In the face of increasing expectations and costly regulations, we are choosing to rely wherever possible on more people dependant and operational controls rather than preferentially opting for new hardware. This strategy [will place] greater demands on work processes and staff to operate within the shrinking margin for error” (CSB, 2007, p.86).

• “Through the Joint Health and Safety Committee, PACE Union 4-449 is notifying the company, BP, of its concern on the issue of the complement of operators relative to providing adequate staffing levels to assure safe and environmentally sound operations at the Texas City Refinery site. Issues include operator staffing levels below the numbers required for ‘safe off staffing’. This involves the day to day operation of units with less than the minimum numbers of operators required. The situations worsen when staffing of extra board decreases to the extent of operators working excessive amounts of overtime, which adds worker fatigue into potential job performance problems” (CSB, 2007, p.285).

Voltar


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Fatores HumanosFatigue Management

• “the CSB concludes that fatigue of the operations personnel contributed to overfilling the tower” (CSB, 2007, p.289).

Voltar


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Fatores HumanosOrganisational change

• “The Texas City site had an overly complex and changing organization which was not conducive to good communication and clear accountability” (Mogford Report, 2005, p.153).

Voltar


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Fatores HumanosWider issues

• “Simply targeting the mistakes of BP’s operators and supervisors misses the underlying and significant cultural, human factors, and organizational causes of the disaster that have a greater preventative impact” (CSB, 2007, p.19).

Voltar


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Erros Potenciais

PIF'sMedidas de Segurança

Mecanismos de Recuperação

Consequências (Falha não

Recuperada)Evitar ou reduzir falhas

Reduzir Consequências/

Melhorar recuperação

Pressão do tempo

Condições climatéricas

Pressão do tempo

Condições climatéricas

Ruído Ambiente

Atenção do operador

Tarefa ou subtarefa

Interromper a operação se possível

Durante esta operação o operador guia-se pelo ruido provocado pela libertação da pressão. A colocação de um manómetro permitiria fazer uma melhor monitorização da pressão.O encerramento da válvula manual e libertação de pressão, a posteriori , para um sistema mais fechado poderá melhorar as condições de segurança para o operador.

Garantir posicionamento do operador de modo a não ser atingido pelos salpicos

�Limitar caudal da válvula de purga para evitar projeções.

SCAT nas condições atuais Medidas Adicionais para FH

Observações

Desacoplar linha em carga (Projeção de produto quente)

Desacoplar linha com carga parcial (Projeção de produto quente).Derrame de pequena quantidade de produto.

Garantir posicionamento do operador de modo a não ser atingido pelos salpicos.Redefinir tipo de luvas a usar para evitar a transmissão de calor.Colocação de aparadeira.

Operação não realizada

Operação incompleta

Abrir válvula de purga suavemente

Abrir válvula de purga suavemente

Despressurizar braço de carga e fechar válvula manual respetiva

SCTA nas condições atuais

o desafiodos fatoreshumanos · 2017-11-23 · seveso_30anos - opcao2 author: goncalo.sousa created...

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