Human Reliability Analysis

1
Human Reliability Analysis

• A review of techniques and applications

By Elizabeth P.
2
Outline

• Review of HRA techniques across disciplines
• Differences among the industries and the
  techniques required
• Benefits and applications

3
List of Acronyms

• HRA- Human Reliability Analysis
• HEP- Human Error Probability
• FTA-Fault Tree Analysis
• ECF- Error Causing Factors
• ELS- Error Likely Situations

• HEI- Human Error Identification
• PIFs- Performance Influencing Factors
• HTA-Hierarchical Task Analysis

4
HRA in Healthcareby Lyons, Vincent, Adams

• The ultimate goal of HRA is to improve
  reliability and safety.
• Why the scarcity of HRA techniques in the
  healthcare system?

5
Differences in Healthcare industry

• Less predictable
• High tolerance for uncertainty
• Industry depends on human-human interaction
• No central focus such as an aircraft or oil
  platform

6
Steps in HRA

• 1.-Data collection
• -ethnographic observation
• -questionnaires
• -structured interviews
• -work sampling

7
Steps in HRA

• 2.-Task Description-allows data collected to be
  presented in a useful form for error analysis an
  quantification
• Common approaches
• --Hierarchical task analysis
• --Cognitive task analysis

8
Steps in HRA

• 3.-Task simulation methods
• Theyre build on task descriptions to consider
  how the performance of a task might change in
  different context under specific circumstances.

9
Steps in HRA

• 4.-Human Error Identification and Analysis
  Techniques
• FMEA-(Failure Modes Effects Analysis)
• SHERPA-(Systematic Human Error Reduction and
  Prediction Approach)
• HEART-(Human Error Assessment and Reduction
  Technique)

10
Steps in HRA

• 5.- Quantification of Errors- consists of
  assigning numbers to uncertain events.
• Ex.blood transfusion
• Problem area
• Compound errors

11
Quantification cont

• HEP can be combined using logical OR gates to
  provide an estimation of an adverse outcome.
• Fault Trees use Boolean logic where probabilities
  are assigned to events, these are then inputted
  to a gate and they result in the calculation of
  the overall probability for the event.

12
Application

• Evaluating risks associated with anesthetist's
  performance.
• Problems from equipment availability to policy
  making can be assessed.
• The application of advanced patient monitoring
  technology and alarms to identify changes
  indicating bleeding or infection.

13
Development and Application of HEI tool for ATC

• By Shorrock and Kirwan

14
TRACEr

• TRACEr- Technique for the retrospective and
  predictive analysis of cognitive errors in air
  traffic control.

15
Function

• TRACEr was used as a predictive HEI technique for
  use with new controller tools, procedures,etc.
• It helped to unpack the nature of errors
  contributing to incidents in the UK.

16
Structure

• TRACEr is based on a modular structure consisting
  of taxonomies.
• 3 Main types of taxonomies
• -Those describing the context in which the
  error occurred
• -Those addressing the production of the
  error
• -Those describing the recovery of the error

17
Origins

• Need was prompted by a feasibility study for the
  use of HRA and HEI techniques in ATC.

18
The Need

• Air traffic was increasing in growth yr by yr.
• That increased the workload for air traffic
  controllers
• Near- miss incidents were also in the rise.

19
Causes

• Some of the causal factors
• -A variety of controller errors involving
  perception, memory,decision making,communication
  and team resource management

20
Problem

• Problem with using existing HRA techniques
• -Lack of structure
• -Excessive jargon
• -Excessive resolution

21
Structure

• TRACEr was based on Wicken(92) framework.
• The concepts within the cognitive framework were
  named cognitive domains

22
Cognitive Domains

• Perception
• Memory
• Judgment
• Action Execution

23
The cognitive framework

• It was used to organize IEMs (internal error
  mode) and PEMs (psychological errror mode)
• IEMs are linked to the functions of cognitive
  domains.

24
Generation of IEMs with TRACEr
25
Conclusion

• TRACEr technique has been implemented as a
  retrospective application such as incidence
  analysis technique and as a predictive HEI
  technique for use with new controller tools and
  procedures.

26
AGAPE-ET A methodology for HEA of emergency tasks

• Human Error Analysis is part of probabilistic
  safety assessment.
• It estimates HEP(human error probability)

27
AGAPE-ET

• A guidance and procedure for human error analysis
  for emergency tasks

28
Function

• Predicts potential weak points related to task
  performance
• Predicts possible error modes using the
  identified contextual information and the
  assessment of the possibility of occurrence in a
  probabilistic value.

29
Structure

• AGAPE-ET its based on a simplified cognitive
  model and a set of performance influencing
  factors (PIFs)
• 1-First, we identify (ECF) and (ELS)
  considering cognitive error mechanisms by
  cognitive function
• 2-Determine error analysis factors based on
  the identification of (ECF) and (ELS).
• 3-Make link between (ECF),(ELS) and error
  modes.

30
AGAPE-ET Cognitive Model

• Stages
• 1-Detection and activation
• 2-Information gathering
• 3-Situational Assessment
• 4-Planning and Decision making
• 5-Task Execution

31
Example of feed bleed

• Depressurize reactor coolant system by opening
  the safety depressurization system while opening
  the pressurizer safety valve
• Inject coolant into the reactor coolant system
• Check its implementation and effectiveness

32
After thought

• Many times the identification of errors or the
  estimation of the probability of their occurrence
  seems to be sufficient in the task to reduce
  errors.
• More work is needed in the prevention aspect of
  HRA.
• Standarization and validation needed
• More domain specific HRA methods

33
(No Transcript)