applied human factors: hazard analysis · the hazard analysis process commences with a preliminary...

Human factors seminar Applied human factors: Hazard analysis Gareth Hughes, Manager Human Factors

December 2015

Asset Standards Authority Applied human factors: Hazard analysis | 2

Agenda

• ASA Human Factors team – who we are • Hazard analysis general principles • Specific tools, techniques, methods and models • Exercise • Q & A


Who we are…

The ASA SQER Human Factors (HF) team are:

• Gareth Hughes - Manager HF • Airdrie Long - Snr HF Specialist • Stuart Hughes - HF Specialist

Asset Standards Authority Purpose, priorities and progress Nick Berry, Manager Industry Engagement

December 2015


Emergency evacuation


Emergency evacuation

Figure 9 - Main fire evacuation assembly area


Consulting and advising across asset life cycle

New engineering drawings and CAD requirements standard

Potential benefits

✓ Consistency across transport organisations in TfNSW cluster

Alignment with AS1100 and industry best practices

First step toward digital engineering (BIM)

No constraint on using a specific software

Common title block formats for all disciplines including tagging and file naming conventions and other metadata requirements (pictured)

✓

✓

✓

✓



Nick Berry Manager, Industry E ngagement 02 9422 7356 [email protected]

mailto:[email protected]


Human factors seminar Applied human factors: Hazard analysis Gareth Hughes, Manager Human Factors

December 2015


This seminar


CHAIR – Application currently has limitations

Construction Hazard Assessment Implication Review = CHAIR CHAIR 1 - is performed at the conceptual stage of a design, which is the best opportunity to make fundamental change, even though much of the design is still to be determined. CHAIR 2 - focuses on construction and demolition issues and is performed just prior to construction, when the full detailed design is known. CHAIR 3 - focuses on maintenance and repair issues and is performed at the same time as the CHAIR 2 study. Developed in the late 1990’s CHAIR is construction focused. CHAIR 3 studies do consider some issues regarding maintainability of the asset but not operability. Note: CHAIR is no longer supported on the NSW Work Cover website.


Safety In Design (SiD) Focuses on safety interventions early in design. This is the most cost effective opportunity to do this. SiD involves the use of: • Hazard identification registers (HAZID) • Risk registers • Risk is eliminated or controlled so far as is reasonably practical

(SFAIRP) levels • Any residual risk is identified and managed by the client • SiD workshops that involve stakeholder representatives

especially the client • Stakeholder consultation should include actual end-users!


SiD in practice - example

Exterior flood light at the top of a three story building

Light fixture rotates inwards to facilitate safe access for maintenance


Lessons learnt – Human factors integration and safety in design • For projects at the simpler end, broadening the Safety in Design (SiD) process can

be sufficient for Human Factors Integration (HFI) – SiD (under the WHS Act 2011) requires consideration of the safety of people

during: Construction Maintenance Operations Disposal

– Broadening the process to include: Operability Maintainability (the ease with which the asset can be operated and maintained)

Note: CHAIR is often provided as evidence of SiD. (Heavily biased towards construction, no longer on WorkCover NSW website) (see T MU HF 00001 GU for further information)


The ASA


The ASA’s objective

The Asset Standards Authority’s objective:

• Is to develop standards to enable AEO’s to deliver: – Assets are both operable and maintainable – Are safe to operate and maintain – Deliver required performance

• Human factors and human interaction is significant in these activities


What are human factors?

• It is the scientific discipline concerned with the understanding of the interactions among humans and other elements of a system and the profession, that applies: – theory – principles – data – methods to design in order to optimise human well

being and system performance.


Human factors

Overall system performance improves when human capabilities and limitations have been addressed in the design


Human factors at the ASA is…

“Human Factors is about ensuring the delivered asset is both operable and maintainable, safe to operate and maintain as well as deliver required levels of performance”

Key points: • It’s about the delivered asset or service (lifecycle) • It starts with good design (at least HF considerations in design) • It’s not only about safety, it’s about delivering to required design

expectations – getting value • To achieve a good asset HF should be incorporated at concept and

design


Human factors in the asset lifecycle

Good asset performance

begins at design

Good design Leads to good asset

performance


Human factors in delivered assets Making operable: • The finished asset works well for

end-users • The needs of the end-user been

properly assessed during the concept and design stages

Making it maintainable: • The finished asset enables

maintainers to keep it working well • Access for maintenance been

considered


Hazard analysis – general principles


Hazard analysis – definitions

Hazard – AS 61508 ‘Potential source of Harm’

Hazard ‘A potential source of harm. A condition that could lead to an accident. A hazard should be referred to a system or product’.


Why perform hazard analysis

• To stop people getting killed or injured

• To enable the development of a SFAIRP design

• To enhance the performance level of the final product

• To provide assurance in the overall quality of the design

• To demonstrate compliance with legislation

• As an afterthought when we have done the design

• Because it says so in the contract

• To keep people happy! • To tick the box


What are the goals of hazard analysis • Completeness • Full list of hazards • Knowledge-based • Take account of past accidents and

current knowledge and previous work (previous projects etc)

• Enable lateral thinking and • Reflect multi-disciplinary understanding of interactions experience between system elements

• To provide robust justification for

• Auditable decisions and content

• Structured • To help completeness

• Efficient • To enable best and appropriate use of resources


What makes for good hazard analysis?

Documentation Scoped

Facilitation

People Preparation

Technique


Exercise – What types of hazards should be identified?


Scope • Design or redesign • Like for Like • Off the Shelf • Simple human interactions or

complex • Predictable or uncertain system

behaviour • System boundary clear or

unclear • Influence of external factors • Influence of related system

elements

To address the requirements of the ASA Human Factors standards you MUST have

sufficient focus on Operability and Maintainability

Which technique?

Simple projects • Past experience (in industry) • Codes and standards • Checklists

• Hazop • Brainstorming

Complex project • Program of Hazard Analysis • Failure Modes Effects and

Criticality Analysis (FMECA) • Fault Tree Analysis (FTA) • Event Tree analysis (ETA)



Engineering codes and standards

Advantages

• Simple to understand and follow

• Legally enforced • Apply to all installations

Disadvantages • Based only on

experience (no prediction)

• Consensus documents (minimum acceptable standard)

• Basis is arbitrary (no risk analysis)

• Other?


Checklists Advantages • All issues on list will be

addressed • Can be done at any

stage in the life cycle • Minimal manpower • Standard checklists

available

Disadvantages • May not be

comprehensive • Rely on past experience

(not predictive) • May be very lengthy • Can be a box ticking

exercise • Need to be kept up to

date


Preparation

• Understand the context and determine the scope of the assessment

• Research past events • Site visit • Understand the human activities required • Identify who should attend (what skill

sets/experience is required) • Prepare documents for meeting • Develop briefing note for participants


Understanding human activities task analysis

Simple Complex


People

• Get the right people • Give people sufficient notice • Confirm attendance close to the day • Try to get as good a room as possible • Limit number to 6 – 8 people plus yourself


Facilitation – basics

• Do the housekeeping • Explain the purpose • Set the ground rules • Explain the process • Try to get everyone involved • Encourage positive

behaviour • Discourage negative

behaviour

A great way to get everyone involved is to start by going

round the table and ask people of the known hazards


Facilitation – best practice

• Use a means of recording that is visual to the whole group. You can then agree wording etc right then and there

• If possible get someone else to do the recording (the better the recording at the time the less effort later)

• Make sure that explanations are explicit and understandable

Tip for participants, if you have something to say don’t

just blurt out, it could interrupt the other persons thoughts. If

it’s not the right time jot it down and say it later. It will actually have more effect!


People – end-user consultation

Have I got the right end user?

Who are my end users?

Have I consulted with them?

How can I make it better for them to

do this?

What are they trying to do?


Exercise - Identifying end-users…


Documentation

• Use predefined format for collecting information at the workshop. This can provide input into the project hazard/risk register

• Include hazard, cause, consequence, current controls, and potential actions required

• Copy of report/results sent to participants for review

• The test of good documentation is that the information should be clear to someone who was not at the meeting


Post Workshop Process

• The final output of the workshop then needs to be reviewed and the proposed actions subject to some form of governance process

• In some cases this may require further analysis such as cost benefit analysis

• Agreed actions then need to be tracked through to completion including any validation & verification activities

The output of the workshop represents the view of a

group of people at a specific time


Hazard analysis in practice

Hazard analysis is the process of recognising hazards that may arise from a system or its environment.

This includes: • documenting undesirable consequences • analysing their potential causes

The hazard analysis process commences with a Preliminary Hazard Analysis (PHA) in the early stages of a project and continues throughout the system product's life cycle.

A good hazard analysis session is well scoped and prepared, well facilitated, structured and well documented.


HAZOP

• Process industry had poor record in 1950-60’s

• Developed by ICI in the UK in the mid 1960's

• Hazard reviews were unstructured and discipline oriented

• Aim was substantially improve safety and operability

• “Structured Brainstorming”

• Based on identifying functional/manageable chunks referred to as ‘nodes’

• Guideword driven - explore ALL possible deviations


HAZOP – Basic Guidewords A hazard and operability study, abbreviated HAZOP, uses guidewords systematically to identify deviations from normal conditions to be further examined by skilled personnel.

Basic Guidewords NO No part of design intent achieved, eg: NO flow, NO level

MORE more of a quantitative property, eg: MORE temperature

LESS less of a quantitative property, eg: LESS pressure

AS WELL AS more of a qualitative property, eg: contamination

PART OF less of a qualitative property, eg: additive present in reduced amount

REVERSE reverse of design intent, eg: REVERSE flow

OTHER THAN something completely different to design intent, eg: product delivered to wrong tank


HAZOP – extended guidewords

Basic guidewords Extended guidewords NO NO FLOW COMPOSITION CHANGE

MORE REVERSE FLOW CONTAMINATION

LESS MORE FLOW RELIEF

PART OF LESS FLOW INSTRUMENTATION

AS WELL AS MORE LEVEL SAMPLING

REVERSE LESS LEVEL CORROSION/EROSION

OTHER THAN MORE PRESSURE SERVICE FAILURE

LESS PRESSURE ABNORMAL OPERATION

MORE TEMPERATURE MAINTENANCE

LESS TEMPERATURE INGNITION

MORE VISCOSITY SPARE EQUIPMENT

LESS VISCOSITY SAFETY


HAZOP – characteristics

• Extremely thorough

• Systematic, structured approach

• Not most intuitive system for new teams

• Multidisciplinary approach

• Relies on expert input... team size


HAZOP – flowsheet

Describe design intention, operating conditions etc.

Consider first or next guide word

Identify all causes and record

Identify all consequences and record

List existing safeguards and record

Take next section

Agree any actions necessary and record

Yes

No Last guide word?


HAZOP - Documentation


Study of procedures

• HAZOP can be applied to procedures

• Modification of standard guideword set • Apply these guidewords to

– actions – sequence – time – information


Study of procedures

Guideword Issue No action Step is missed or omitted operation did not occur

/ action impossible / equipment not ready Operator does more than intended / other actions More action occur affecting this operation

Operation does less than intended / equipment

Less action does not perform as required / not enough time to complete the step Wrong action Operator pulls wrong lever, reads wrong

instrument / closes instead of opens / performs different or out of date procedure / performs two or more steps at once


Study of procedures Guideword Issue No information No feedback from system / procedure does not specify expected performance / no actions for emergencies or results specified

Too much information Step is confusing / too much detail / too many alarms or signals / contains unnecessary information / too many tasks / information overload

Less information Insufficient information to perform properly / expected result not specified / no start or end conditions /

insufficient information to cope with emergency or unusual r esults

Wrong information Information provided is wrong or out of date / typo / written instructions contradict oral, or other procedures, or steps in this procedure


Study of procedures

Guideword Issue More time Operator takes longer than necessary over

action/starts next action later than expected Less time Insufficient time allowed/operator carries out

action too quickly/insufficient time to warm up or cool down/equipment limitations Out of sequence This step occurs too soon or too late/operator

performs step at wrong time/equipment not in proper state

Example – HAZOP results


Guideword Deviation Cause Consequence Current safeguards

Recommendations Action by

No Flow Valve stuck in closed position

Operational delay Potential damage

to pump

Pump design Provide positive feedback of flow to

operator

GJH

Operator fails to open valve

Operational delay Potential damage

to pump

Operator to develop procedure

and training

Provide positive feedback of flow to

operator Aide memoir to be

provided on site Valve position to be

clearly indicated to operator

GJH DVX DVX


Brainstorming – SWIFT

Structured What If Technique


SWIFT characteristics

• Appropriately thorough

• Systematic

• Multidisciplinary team

• Analytical approach

• Relies on expert input


Development of checklist questions The key inputs to the development of checklist questions: • Task analysis • Review of past incidents • Review of relevant:

o Codes o Standards o Legislation

• Other checklists


SWIFT procedures

• Pick a section • Discuss regulatory issues • Determine design intent • Choose a question category • Ask What If questions • Answer What If questions • Use checklist to prompt questions

• Select next question category • Discuss other regulatory issues


Brainstorm a list of hazards

• What if?

• How?

• Is it possible?

• Has it even happened?


SWIFT documentation

The recorder would list the findings under the followingcategories:

• Question

• What-if Question • Consequences • Safeguards • Recommendations


SWIFT example – filling a car

Question Category

What if Consequences Safeguards Recommendations Action by

Human Factors

What if the driver puts diesel in a petrol car

Clogging of fuel system Costly repairs Divorce!

Make entry to fuel tanks different sizes Clearly label diesel pump Separate diesel pumps from petrol pumps Don’t own a diesel and petrol car

Only fill up own car Self


Exercise – SWIFT


Exercise

What do you see as the main differences between HAZOP and SWIFT

Think…


Exercise – Lifecycle

Where do you think the list of techniques fits on the life cycle diagram?


Conclusions

• It IS worth doing well • Scale of exercise appropriate to the project • Several available techniques from simple to complex • Some are team-based (HAZOP) and individual (FMEA) • Must be structured and documented • You MUST ask the questions about what the people need

to do to operate and maintain the system. Best source of information is from end users

applied human factors: hazard analysis · the hazard analysis process commences with a preliminary...

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