Transcript Prezentace aplikace PowerPoint

reflection
by
Ing. Martin K r š k o
RISK CONSULT Ltd.
Račianska 72,
831 02 Bratislava, SLOVAKIA
EU
Directive 96/82/EC
Seveso II
One of the reasons for “upgrade“ has been
the changing attitude from considering
exclusivetly technical safety aspects forward
to find its real causes – in most cases the HF
Sice 1st of january 2004 an amendment of
the Directive 96/82/EC has been in force –
technical and organiastional safety easures
are far from being perfect and more
improvements are to come.
SK
Act n. 261/2002 Z.z. on the prevention
of major major industrial accidents
and on changing and amending other acts
+
2 dcrees (489/2002 Z.z. and 490/2002 Z.z. )
HF influence on safety is recognised and covered
by several articles and in the safety documentation.
However, HF analysis is often neglected.
Focus on the required safety documentation
- few reasons for getting concerned…
- where is HF involved?
- “how to” approaches and tips.
- documentation writing.
The Seveso II requirements fulfilment differ in the different countries.
Current practice is that some requirements are neglected.
Most of the Safety reports worked out by the operators has been returned for
insufficient stress on various fields.
Certain requirements are often completely ignored / omitted.
HF is considered very superficailly, more qualitatively than quantitatively, but
the most of all cases ignored / omitted even if the HF is recognised to be the most
contributing factor in the major industrial accidents which took place.
HF importance is underlined by recnet major industrial accidents, each had
had a considerable contribution from the human failure point of view.
technical
failure,
vis major…
Human factors has seemed
–too ambiguous
–too involved
–too comprehensive
–too difficult?
HF
For the industry to embrace human factors in a committed way, we need:
– More education
– More practical guidelines
– Additional technical information
– Benchmarking tools
– To do something about it - now!
The safety documentation in the field of the prevention of major accidents is
required by the act n. 261/2002 Z.z.
- major accident prevention policy - MAPP
- safety management system - SMS
- risk assessment / analysis
- emergency planning (internal / external)
- safety report
Hidden responsabilities – MAPP and SMS
MAPP and SMS are managing documents, which provide the basis for dealing with
the HF in relation to the potential major accident occurrence.
This documentation is supposed to be the output of the HF analysis –
measures resulting from the HF assessment and analysis.
Covered fields:
-organisational structure
- risk identification and assessment
- operation management
- change management
- emergency planning
- performance monitoring
- audits
Observation – the notification and the risk sources identification does not care about
the influence of the HF on the safety level.
Risk assessment and analysis
Proper quantitative risk assessment is a matter of evaluating both
- technical failures resulting into an accident
- human failure resulting into some technical failure causing an accident
In general, technical aspects are easier to cope with (generic databases, methods
for processing failure data, availabilities, etc.) than human failure aspects.
This fact is caused mainly by the complex and unpredictable nature of the
human failure parameter.
cause of human failure
- wrong reflexion
- insufficient training, education
- insufficient instructions
- unsuitable control systems
- etc.
cause of thechnical failure
- mismatch of control operations
- disconnection of safety mechanisms
- communication errors
- process control failures
- etc.
There are two main streams in integrating the HF into the quantitative risk assessment:
- an attempt should be made to treat the HF explicitely so that the QRA directly reflects
the influence of the technology operators and maintenance on the occurrence of
accidents.
- the QRA should be hardware-focused and the HF should be “hidden” in the failure
rate of a certain component in order to reflect an average standard of human
performance
…a bit of heuristics…
These two approaches can be combined in order to obtain a very representative
qualitative assessment reflexing the “status quo” of the system.
This can be achieved by careful choice of the basic events:
- detailed development of the failure tree where appropriate
- integrate the HF into equipment where suitable
PHA
Select Section to Study
HEA
Identify activity and tasks
Apply Deviation/Guideword
Breakdown tasks into necessary steps
Identify Causes/What If’s
Identify human errors that could
occur during each step
Evaluate Consequences
of Deviation/Cause
Determine Likelihood of Scenario
Perform Risk Ranking
Identify Possible Recommendations
Determine the consequences of the error
Determine likelihood of scenario
Rank the consequences and likelihood
Identify remedial measures for
high risk scenarios
HF
HF
HF
HF
HF
Generic Human Error Probability of Operator's Fail to Diagnose/Respond to Alarm Signal as Function of
Time after Signal
1
1
1
1
10
0.01
0.1
1
1
20
0.001
0.01
0.1
30
0.0001
0.001
0.01
60 0.000003
0.0001
0.003
1500
3E-07 0.00001
0.0003
Probability of Failure on Dem and (unitless)
0.1
0.01
0.001
Low er Bound HEP
Median HEP
Upper Bound HEP
0.0001
0.00001
0.000001
0.0000001
1
10
100
1000
Tim e T in Minutes after Annunciation of Abnorm al Situation
10000
All this theory has to be found in the safety documentation of an establishment.
An universal approach may look like:
Description of the work position
Its potential to cause an accident
Evaluation of the
human-technology relationship
Quantitative evaluation of the
human failure influence
Suggestion of
corrective / preventive actions
In order to include the HF assessment and analysis into the safety documentation,
one can follow these steps:
- identification of work positions which can be directly responsible for the generation of a
major accident
- identification of common events that may be generated by the technical system and by the HF
- assessment and analysis of the HF liability
- critical points in the human-technology system
- possible failures, errors and its causes
- qualitative analyses of the human factor reliability (like HRA, THERP, HAZOP, SHERPA
etc.)
- categorisation of the system demandingness (technology complexity, operation management
complexity, communication, etc.)
- workforce selection based on relevant criteria, selected behavior shaping factors, etc.
- regular (time scheduled) evaluation of the employee suitability
- regular control of the working environment (ergonomy, user friendly software, etc.)
- regular information to the employees, “work-caused risk awareness”, risk perception, etc
- regular exercices and formation
- possible back-up of the most sensitive positions (personal or technical)
HF is involved through the entire safety documentation.
HF can be included in the safety documentation in a variety of ways, no unified
concept is adopted.
The Seveso II requirements concerning the human factor are to be assessed and
considered separately, depending on the establishment nature, the dangers / risks
emanating from the technology, etc…
The output of the HF analysis is to be incorporated into management documents,
so that the improvements designed are really improved…
Thank you for your attention!