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Introduction – about meChemical engineerHuman factors consultant for 10 years – oil, chemical, gas industry – COMAH sitesSelf-employed since January 2005Recent clients include Shell, Corus, Lucite, Novartis, Jacobs, Centrica, CapitalOne, DTiHealth & Safety Executive projects
SupervisionCOMAH evaluationControl rooms.
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Purpose of the presentation
Give you an appreciation of human factorsWhat is it?Why is it important?How can you apply it to controlling major hazards?Human factors in designExpectations of the Health and Safety Executive
Overview of a two-day courseHuman factors in COMAH.
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Human Factors and Ergonomics
What are they?Same thing or different?Why are they important?
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Ergonomics
From the Ergonomics Society website at www.ergonomics.org.uk
The job must ‘fit the person’ and should not compromise human capabilities and limitations.
The application of scientific information concerning humans to the design of objects, systems and environment for human use.The interaction of technology and people Basic anatomy, physiology and psychology Objective to achieve:
The most productive use of human capabilities Maintenance of human health and well-being
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Physical demands - musculoskeletal disordersPsychological demands - stressSocial conditions - job satisfactionHuman error - cause of major accidents.
Human Factors
“Environmental, organisational and job factors, and human and individual characteristics which influence behaviour at work in a way which can
affect health and safety”
HSG48 Reducing error and influencing behaviour
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Human FactorsWhat are people being asked to do(the task and its characteristics)?
Who is doing it (the individual and their competence)?
Where are they working (the organisation and its attributes)?
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There is a large overlap
ErgonomicsHuman capabilitiesHardware designWork stationsUser interfacesWorking environmentManual handlingPersonal safety, health and well being
Human factorsWhole systemOrganisationCultureTasksErrorsProceduresTraining and competenceMajor hazard
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Behavioural safety
Tends to be more concerned withPhysical activitiesPersonal safety accidentsFailures of people at the sharp end
The premise is that people are free to choose the actions they makeHuman factors is based on the principle that people are ‘set up’ to fail
Management and organisational root causes.
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Major accidents
Texaco - Pembroke Herald of Free Enterprise Chernobyl
Clapham Junction Esso - Longford Fixborough
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Why is human factors important?
Up to 80% of accident causes can be attributed to human factorsAll major accidents involve a number of human failuresHuman factors is concerned with
Understanding the causes of human failuresPreventing human failures
“Underlying accident causes are faults of management and supervision plus the unwise methods and procedures that management and supervision fail to correct…” (Heinrich 1931).
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Causes of human failures
Job factorsIllogical design of equipmentDisturbances and interruptionsMissing or unclear instructionsPoorly maintained equipmentHigh workloadNoisy and unpleasant working conditions
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Cause of human failure (continued)
Individual factorsLow skill and competence levelsTired staffBored or disheartened staffIndividual medical problems
Organisational and management factorsPoor work planning, leading to high work pressureLack of safety systems and barriersInadequate responses to previous incidentsManagement based on one-way communicationsPoor health and safety culture
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Video
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• 1 way to undo• 40,0000 ways to reassemble
Procedure UseNot something people like to do!Depends on
Task experienceTask complexity(Perception of) task criticality
Closely related to competencyCannot write a procedure for every taskJob aids can be very useful
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Training and competence
They are not the same thing!Requirements must be specific – define the skill, knowledge and/or understanding to be achievedMust reflect how tasks are performed (based on written procedure)Must be evaluatedCompetence can degrade.
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Human factors in design
Human factors considered throughout designIntegral not separate activityRequires human factors expertise
Based on end user requirementsInvolved throughoutUser trials
AnalysesTask analysisInformation needs analysisCommunication link analysisWorkload assessment.
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Critical tasksOperating:
Start up and shut downBulk loading and unloadingComplex manifolds and line upsContinuing to operate whilst some elements are inoperableResponding to emergencies.
MaintenanceWork on live systemsIntrusive workReassembly of items critical to pressure envelopeResetting of safety critical elements.
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Man against the machine
Humans are better atDetecting small visual or acoustic signalsPerceiving patternsImprovisingBeing flexible in approachExercising judgement
Machines are better atResponding quickly to control signalsApplying force smoothly and preciselyPerforming repetitive tasksHandling highly complex situations
Not possible to engineer-out human involvementAutomation usually reduces the day-to-day human involvementReliance on error free maintenance, testing etc.
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Control Room DesignGive adequate consideration to human factors for normal and abnormal conditions
Number of people (more & less than ‘normal’)
Man-machine interface is a combination of displays, alarms and input devices Should be designed on a full task analysis
Should map activities to controlsRecognise potential under & over load of operatorsFeedback that actions have been successfulOpportunity to correct errorsInform of deviations from safe operating levels
Frequency, proximity and importance.
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Alarms - EEMUA Guide
Long term average alarm rate – no more than one every 10 minutesNo more than 10 alarms in the first 10 minutes of a major plant upsetPrioritise
High – 5%Medium – 15%Low – 80%.
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Health and Safety Executive
Human factors is being seen as a high prioritywww.hse.gov.uk/humanfactors
Specialist team within HIDInspection, investigation, expert witness, advice, guidance and researchProvide specialist supportTraining field inspectors
Aim – ‘To drive continuous improvement in the management of human performance in the control of major accident hazards.’
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HSE’s concern with current approaches
Overoptimistic assumption of what people will doIntervene “heroically”Always follow proceduresWell trained, highly motivated & always presentWill take immediate, appropriate action
Too much emphasis on personal safety rather than how errors can cause major accidentsFocus on technician errors - managers, designers etc. don’t make errors!Failure to deal with human factors with same rigor as for process and engineering issues
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HSE’s Top Ten Human FactorsOrganisational changeStaffing levels and workloadTraining and competenceAlarm HandlingFatigue from shiftwork & overtimeIntegrating human factors into risk assessment and investigation Communication/interfacesOrganisational cultureHuman factors in designMaintenance error
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What the HSE is looking for
Knowledge
Understanding
Application
Do you know what human factors is?
Do you understand human factors?
Do you know your limitations?
Do you have the available guidance?
Do you have access to competent help?
Is there a ‘competent person’ on site?
Is there evidence of human factors in your systems?
Do you monitor and review?
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Have enforced because of
Organisational changeHours of workWorkload and staffingCompetence assuranceHuman factors risk assessment for batch process
No appeals on noticed issued to date
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Specific requirements
Task analysisCompetence assurance programErgonomic standards
ProceduresInterface design
Staffing level assessmentFatigue assessment and managementDesign and procurement proceduresShift handover.
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Task Analysis
Separator tasks
Start up unitStart/stop individual pumpsOpen/close wellsWater wash separatorRespond to unit trip
HighLowMediumMediumHigh
Criticality
Offshore Technology Report OTO 1999 092http://www.hse.gov.uk/research/otopdf/1999/oto99092.pdf
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Hierarchical Task AnalysisWater wash
production separator
2.1 Put override on
2.2 Start wash water pump
2.3 Open wash water inlet valve
2.4 Put flow control valve on manual
2.5 Open flow CV to maximum
SS CRFO CRFO
1. Line-up water to separator
2. Start washing
3. Monitor water outlet for oil
4. Return to normal
Plan: Do 1 then 2Do 3 until water is clearThen do 4
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Staffing Arrangements Assessment
Not calculate minimum or optimum number of staffEnough people to detect, diagnose and respond to potential or actual emergency situationsMore people not always the solutionStaffing arrangements + technology
YES
YES NO
NO
Physical assessment decision trees
Individual/organisational ladder assessment
Energy Institute User Guide ww.energyinst.org.uk/humanfactors/staffing
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HSE RR 292/2004 www.hse.gov.uk/research/rrhtm/rr293.htm
SupervisionManagement functionPerformed by one or more people, within and/or external to the teamHas been overlooked in recent yearsMany control room operators perform supervisory activities.
Rotating leadership
Coach / mentor
Team appointed
leader
Management appointed
leader
Traditional hierarchy
True SMT
Supervision is team led
Supervision is management led
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ALARP
As Low As Reasonably PracticablePresumption is that you will implement ‘good practice’ risk reduction measures
Need to demonstrate sacrifice is grossly disproportionate to the benefitRisk reduction would be minimalWould lead to greater risk else-where
Holistic approachRisk of the whole facility.
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Demonstrating ALARP
Answer these two questionsWhat more could be done?Why have we not done it?
For example, could you:automate more? – Ironies of automationhave more automatic protection? – Over-reliancehave more procedures? – Usability concernsdo more training? – Only (small) part of competenceemploy more people? - ???
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Costs of Accidents
Piper Alpha - $2.5 billionExxon Valdez - $3.5 billionGrangemouth - $100 million
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Benefits of Addressing Human Factors
Integration during design 1
Improved safety = less accidentsImproved working conditions = less health problemsMore efficient operation and maintenanceLess down timeIn some cases lower CAPEX
Less than 1% of engineering costs 2
1 - MW Kellogs - Presented at Petroleum Institute 20012 - Shell - Presented at Houston 2002
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Risk Reduction Strategy
Always look to remove or reduce hazard firstSpecify hardware controls – but ensure does not affect operabilityProcedural controls and rules – must be practical and realistic under all conditionsPPE and mitigation are secondary, in addition to the above
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A changing world
New technologyMore automationLess peopleMore remoteDifferent team structuresEvolving jobs
More passiveMore lonelyMore responsibility.
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“An airline would not make the mistake of measuring air safety by looking at the
number of routine injuries occurring to it staff”
A. Hopkins - Lessons from Longford
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