1 human factors course session 1 eric davey crew systems solutions 2007 march 28
TRANSCRIPT
1
Human Factors Course
Session 1
Eric DaveyCrew Systems Solutions
2007 March 28
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NASA POES Spacecraft - Anomaly
Incident 1
3
NASA POES Spacecraft - Anomaly
Incident 1
4
Accident Findings
Causal Factors Procedural Compliance
Sept 04 - Crew 1 - Bolt removal without documentation Sept 06 - Crew 2 - Cart use without verifying configuration
Consequences Launch delay ~ 2 years Significant rework and retest
Incident 1
5
Other Possible Accident Factors
Design Spacecraft configuration - Tall Workplace - Service or transport Tools - Bolt visibility and interlocks
Operations and Organizational Independent verification Tag-out on configuration changes Shift change or work resumption practice Time - Saturday following supper Staffing - Numbers and experience
Incident 1
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American Airlines Flight 587
Incident 2001 November Airbus 300-600 departing New York for Puerto Rico Encounters wake turbulence on takeoff Tail/rudder failure and separation Loss of control
Consequence 265 lives lost
Incident 2
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American Airlines Flight 587
Headline Chronology 2002 Feb
CBS Dangerous Rudder Movements
2004 Oct BBC Queens crash blamed on co-pilot Globe Pilot error blamed in US Airbus crash CNN NTSB: Copilot error caused 2001
crash
Incident 2
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American Airlines Flight 587
Causal Factors Environment Departure scheduling - turbulence
Uncertainty in turbulence location Climb-out - High airspeed and airframe
load Training Response to wake turbulence
Roll recovery with aggressive rudder use Design Rudder sensitivity - full deflection
A300-600 32 lb and 1.2 in travel
Other Planes 125 lb and 4.0 in travel
Communication Breakdown between designer & airline
Incident 2
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Patient Hospital Safety - Canada
Adverse Event Study - 2000 AE - Unintended patient injury by medical system
Impact Incidence(Per 100 Admissions)
Adverse Event
Incidence(People/Year)
Preventable AE
AE - Death
Preventable AE - Death
7.5
2.8
1.5
0.66
185,000
70,000
37,000
16,000
Incident 3
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Patient Hospital Safety - Canada
Types of Complications Wrong medication or dosage 1 in 9 Infection Adverse drug reaction Hospital acquired injury
Consequences 1.1 million added days in hospital/year ~$750 million
Patient and family inconvenience Lost work time
Incident 3
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Problems with Medication Abbreviations
Common Misinterpretations
Abbreviation Meaning
µg
Misinterpretation
microgram mg - milligram
qn nightly qh - hourly
q1d daily q.i.d. - four times daily
HS half strength hs - bedtime
IJ injection IV - intravenous
Incident 3
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About this Course
Subject Application of human factors criteria and methods in design
to support users to achieve effective and error free performance
Context Facility design, training & operations
Outcomes Operational effectiveness Safety
Introduction
13
Course Structure
Four Sessions Issues with human-systems operation
Break
Understanding human capabilities and performance
Lunch
Designing to support human-system interaction
Break
Applying human factors - Group exercise
Introduction
14
Eric Davey
Education Electrical Engineering - Toronto & New Brunswick
Experience Applied Nuclear R/D - Instrumentation & Systems - 15 years - AECL
Chalk River Power Reactor Control Rooms & Operations - 15 years
Projects - Human Factors Task characterization and analysis Workspace design Systems development - Annunciation and Displays Operations assessment - Changes Regulatory compliance
Introduction
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Session 1 - Issues with human-systems operation
Topics Incident examples Course purpose & content Supporting human performance
Symptoms of problems Range of factors Approaches
What is human factors? Examples of assessing/providing task support
Introduction
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Symptoms - Lack of Support
User’s View What is it doing now?
Why did it do that?
How did I get into this state?
How do I stop it from doing this?
How do I get it to do what I want?
It usually works - what's changed?
Background
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Symptoms - Lack of Support
Trainer's View System takes too much time to
train
We don't train for every situation
We don't train on all features
System uses non standard conventions
Hopefully they will learn it on the job
Background
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Symptoms - Lack of Support
Designer's View System performed as designed
System design met requirements
System was not designed for that operating condition
System works okay, some don’t understand it
Background
19
Symptoms - Lack of Support
Facility Impact Workarounds
Work delays & inefficiencies
Unrealized production
Events Disruptions in production Safety challenges
Background
Difficulties in Productioncan be precursors to
Safety challenges
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Why Human Performance is of Concern?
Responsibility People design, direct and supervise operation
Human Impact Pervasiveness of human involvement
Fallibility Human behaviour is not fail proof
Experience Human behaviour is a major contributing factor to
Safety challenges Production disruption & inefficiency
Background
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What Could Be Mismatched or Missing?
Support for Desired Performance
Background
PhysicalDesign
OperationalEnvironment
Person
DesiredPerformance • Task
• Supervision• Procedures• Practices• Culture
• Education• Job training• Experience• Fitness
• Workspace• Automation• Feedback• Reliability
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What Could Be Mismatched or Missing?
Support for Desired Performance
Background
• Location• Size• Colour
Political
Organization
Team
Cognitive
Physical
DesiredPerformance
• Info content• Info structure• Info relations
• Communication• Authority• Roles
• Policy • Law• Regulations
• Culture• Priorities• Resourcing
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A Model of Facility Operation
Background
Agents
Actions
Goals
Functions
Needs
WorkingTogether
Well
People Systems
Automation• Control• Monitoring• Detection• Respond to user
Tasks• Configuration• Supervision• Intervention• Servicing
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How Might Problems Occur? - Design
Background
Goals
Functions
Training(People)
Design(Systems & Automation)
Procedures(Tasks)
Step 1
Step 2
Step 3
Design for Accessibility• Design without task or user description
WorkingTogetherLess Well
Procedureand peoplecompensation
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How Might Problems Occur? - Operations
Background
Goals
Functions
PeopleSystems
& Automation
Procedures(Tasks)
WorkingTogetherLess Well
Equipment aging
Modified goals
Changes
Environmentalchange
Additional tasks
New functionality
Skill loss
Stress
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How Might Problems be Reduced?
Background
Goals
Functions
Training(People)
Design(Systems & Automation)
Procedures
Step 1
Step 2
Step 3
Design for Use• Design with task and user description
Step 0
Control Usage• Limit changes and monitor impacts
TaskDescription
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What is Human Factors?
Knowledge About the capabilities of humans and their interaction with
technical systems
Criteria and Methods For designing systems and workspaces so that user task
needs and operational objectives are successfully met.
Definition & Examples
So consistency in performance excellence can be achieved.
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Example - Audible Communication
Understanding Speech - Background Noise
Normal speech levels (1m) = 55 to 75 dB
Context
Design Criteria
Speech vs Background ConditionUnderstanding
Concentrated listening
Concentrated listening
Full
Full
Partial
> 5 dB
0 dB
< 5 dB
None
Definition & Examples
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Example - Visual Communication
Reading at a Distance
Definition & Examples
HeightSpacing
LuminanceContrast ratio
Factors
Design Criteria
Legibility
Distance = 2.5 m
Character Height minutes - arc cm
1.06
1.66
5
14
22
Character - Minimum
Words - Minimum
Words - Preferred
0.38
A A A
A A A
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Exercise - Alarm Display Legibility
Situation Addition of alarm number to existing alarm display Design solution
Reduce character spacing to accommodate addition of alarm number
Questions Impacts on:
Viewing distance - Legibility User behaviours Task performance
Definition & Examples
C A R CAR
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Exercise - Alarm Display Legibility
Characterizing Impact Measure viewing distance
5x with old display 5x with new display
Calculate average viewing distance Repeat for 4 subjects Determine impact of display change
Definition & Examples
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Results Discussion Viewing distance impact
Other influencing factors Room illumination Text colour Subject visual acuity Subject familiarity with alarm messages
Exercise - Display Legibility
Definition & Examples
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Example - Display Design
Developing & Maintaining Plant Awareness
Current & PastPlant State
Expected Plant State
Definition & Examples
• Perception• Comprehension• Projection
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Understanding Monitoring Behaviour
Context Stable operation Variability in practice
Questions Objectives Strategies Parameters Representations Relationships
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Definition & Examples
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Monitoring Objectives
Periodic examination of current plant state to:
• Detect a change from normal in key indications
• Confirm goals selected are being achieved
Definition & Examples
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Operating Goals
Safety and Production Performance Health
DesignBasis
Licensed Operating
Range
Target Setpoint
Current Operating
Point
*
OperatingRange
Definition & Examples
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A Monitoring Strategy - Automation Functions
Heat Transport Pressure/Level
ReactorPower
BoilerLevel
Boiler Pressure
ElectricityGeneration
DeaeratorPressure/Level
OperatorSetpoint
Definition & Examples
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Types of Information Control Program Information
Process Setpoint
Disturbances
ProcessOutput
Continuous Feedback
Function
InternalPerformance Measures
• Performance• Health
Indication
Periodic Feedback
Adjustment
Definition & Examples
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Information Form
13:44:19 100.0
Representations which support: Value comparisons Parameter trending with time
101
98.4
95
PSA
RP SETPOINT%FP
PLIN
LIN N%FP
101
98.6
95
Trend Current Value
• Relationships
Bar Chart
96.0
Definition & Examples
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Enhancements to Existing Displays
Trend Display - Reactor Power
PLIN
LIN N%FP
101
98.5
95
80.0
44.19
20.0
101
98.4
95
+1.0
0.01
-1.0
PERR
RP ERROR%FP
PSA
RP SETPOINT%FP
LEVAV
AVERAGE ZONELEVEL %FP
• Process Outputs
• Process Setpoint
• Internal Measure
Organization
RangeAdjustments
Parameter Substitutions
Definition & Examples
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Example - New Display Concepts
Heat Sink Monitoring - Outages
Fuel Decay Heat Heat Transport Circulated Cooling Service Water
Shutdown Days
Pow
er (
MW
)
Pow
er (
MW
)
Pow
er (
MW
)
Pow
er (
MW
)
Expected Decay Heat
Actual Heat Produced
Heat RemovedFirst Heat Sink
Heat RemovedSecond Heat Sink
• Heat Sink• Flow• Inventory
• Heat Sink• Flow• Inventory
• Heat Sink• Flow• Inventory
• Time Zero
Reactor Delta T Heat Sink Delta T Heat Sink Delta T
** * *
Definition & Examples