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There are obvious economic arguments to managing safety - this slide illustrates some of the costs of high-profile accidents. But as I said before, failures of management systems can influence not just major accidents like these, but near-misses and less significant incidents. If you manage the factors that control small incidents then there is a very good chance that you will not have major incidents like these.
2006 IChemE Manchester Branch - Human factors & risk management
Tel: 01492 879813 Mob: 07984 284642
Human Factors & Risk Management
Introduction – about me
Human factors consultant for 10 years – oil,
chemical, gas industry – COMAH sites
Self-employed since January 2005
Recent clients include Shell, Corus, Lucite,
Novartis, Jacobs, Centrica, CapitalOne, DTi
Health & Safety Executive projects
Purpose of the presentation
Give you an appreciation of human factors
What is it?
Why is it important?
How can you apply it to controlling major hazards?
Human factors in design
Expectations of the Health and Safety Executive
Overview of a two-day course
Human factors in COMAH.
Human Factors and Ergonomics
What are they?
Same thing or different?
Why are they important?
From the Ergonomics Society website at
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
Physical demands - musculoskeletal disorders
Psychological demands - stress
Social conditions - job satisfaction
Human error - cause of major accidents.
“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
What are people being
asked to do
(the task and its
Who is doing it (the
individual and their
Where are they working
(the organisation and its
There is a large overlap
Personal safety, health
and well being
Training and competence
Tends to be more concerned with
Personal safety accidents
Failures of people at the sharp end
The premise is that people are free to choose
the actions they make
Human factors is based on the principle that
people are ‘set up’ to fail
Management and organisational root causes.
Texaco - Pembroke Herald of Free Enterprise Chernobyl
Clapham Junction Esso - Longford Fixborough
Why is human factors important?
Up to 80% of accident causes can be attributed
to human factors
All major accidents involve a number of human
Human factors is concerned with
Understanding the causes of human failures
Preventing 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).
Causes of human failures
Illogical design of equipment
Disturbances and interruptions
Missing or unclear instructions
Poorly maintained equipment
Noisy and unpleasant working conditions
Cause of human failure (continued)
Low skill and competence levels
Bored or disheartened staff
Individual medical problems
Organisational and management factors
Poor work planning, leading to high work pressure
Lack of safety systems and barriers
Inadequate responses to previous incidents
Management based on one-way communications
Poor health and safety culture
• 1 way to undo
• 40,0000 ways to
Not something people like to do!
(Perception of) task criticality
Closely related to competency
Cannot write a procedure for every task
Job aids can be very useful
Training and competence
They are not the same thing!
Requirements must be specific – define the skill,
knowledge and/or understanding to be achieved
Must reflect how tasks are performed (based on
Must be evaluated
Competence can degrade.
Human factors in design
Human factors considered throughout design
Integral not separate activity
Requires human factors expertise
Based on end user requirements
Information needs analysis
Communication link analysis
Start up and shut down
Bulk loading and unloading
Complex manifolds and line ups
Continuing to operate whilst some elements are inoperable
Responding to emergencies.
Work on live systems
Reassembly of items critical to pressure envelope
Resetting of safety critical elements.
Man against the machine
Humans are better at
Detecting small visual or
Being flexible in approach
Machines are better at
Responding quickly to
Applying force smoothly
Performing repetitive tasks
Handling highly complex
Not possible to engineer-out human involvement
Automation usually reduces the day-to-day human
Reliance on error free maintenance, testing etc.
Control Room Design
Give adequate consideration to human factors for normal and
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 controls
Recognise potential under & over load of operators
Feedback that actions have been successful
Opportunity to correct errors
Inform of deviations from safe operating levels
Frequency, proximity and importance.
Alarms - EEMUA Guide
Long term average alarm rate – no more than
one every 10 minutes
No more than 10 alarms in the first 10 minutes
of a major plant upset
High – 5%
Medium – 15%
Low – 80%.
Health and Safety Executive
Human factors is being seen as a high priority
Specialist team within HID
Inspection, investigation, expert witness, advice,
guidance and research
Provide specialist support
Training field inspectors
Aim – ‘To drive continuous improvement in the
management of human performance in the
control of major accident hazards.’
HSE’s concern with current approaches
Overoptimistic assumption of what people will do
Always follow procedures
Well trained, highly motivated & always present
Will take immediate, appropriate action
Too much emphasis on personal safety rather than how
errors can cause major accidents
Focus 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
HSE’s Top Ten Human Factors
Staffing levels and workload
Training and competence
Fatigue from shiftwork & overtime
Integrating human factors into risk assessment
Human factors in design
What the HSE is looking for
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
Do you monitor and review?
Have enforced because of
Hours of work
Workload and staffing
Human factors risk assessment for batch
No appeals on noticed issued to date
Competence assurance program
Staffing level assessment
Fatigue assessment and management
Design and procurement procedures
Start up unit
Start/stop individual pumps
Water wash separator
Respond to unit trip
Offshore Technology Report OTO 1999 092
Hierarchical Task Analysis
2.2 Start wash
2.3 Open wash
water inlet valve
2.4 Put flow control
valve on manual
2.5 Open flow CV
SS CRFO CRFO
1. Line-up water
3. Monitor water
outlet for oil
Plan: Do 1 then 2
Do 3 until water is clear
Then do 4
Staffing Arrangements Assessment
Not calculate minimum or optimum number of staff
Enough people to detect, diagnose and respond to potential or actual emergency situations
More people not always the solution
Staffing arrangements + technology
Energy Institute User Guide ww.energyinst.org.uk/humanfactors/staffing
HSE RR 292/2004 www.hse.gov.uk/research/rrhtm/rr293.htm
Performed by one or more people, within and/or
external to the team
Has been overlooked in recent years
Many control room operators perform supervisory
As Low As Reasonably Practicable
Presumption is that you will implement ‘good
practice’ risk reduction measures
Need to demonstrate sacrifice is grossly
disproportionate to the benefit
Risk reduction would be minimal
Would lead to greater risk else-where
Risk of the whole facility.
Answer these two questions
What more could be done?
Why have we not done it?
For example, could you:
automate more? – Ironies of automation
have more automatic protection? – Over-reliance
have more procedures? – Usability concerns
do more training? – Only (small) part of competence
employ more people? - ???
Costs of Accidents
Piper Alpha - $2.5 billion
Exxon Valdez - $3.5 billion
Grangemouth - $100 million
Benefits of Addressing Human Factors
Integration during design 1
Improved safety = less accidents
Improved working conditions = less health problems
More efficient operation and maintenance
Less down time
In some cases lower CAPEX
Less than 1% of engineering costs 2
1 - MW Kellogs - Presented at Petroleum Institute 2001
2 - Shell - Presented at Houston 2002
Risk Reduction Strategy
Always look to remove or reduce hazard first
Specify hardware controls – but ensure does not
Procedural controls and rules – must be practical
and realistic under all conditions
PPE and mitigation are secondary, in addition to
A changing world
Different team structures
“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