Nov.19, 2004

1
Task Analysis A Foundation for Safety

• Nov.19, 2004
• Jon Stuart, Ph. D.

2
Presentation Overview

• What is task analysis?
• The benefits
• Critical components of task analysis
  example
• Using task analysis across the organization
• Practical considerations

3
Task Analysis

• Your main goal is improving safety
• A key component of improving safety is reducing
  human error
• Reduce the number of errors
• Put defenses in place to reduce their impact
• Why use task analysis?
• Because it builds a concrete, thorough
  description of what people do

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Benefits of Using Task Analysis

• Systematic (thorough)
• Easy to learn
• Demystifies human behavior dont need to be a
  psychologist
• Clear communication of outputs
• To subject matter experts to safety teams
• Easy to adapt
• To different analyst styles to a wide range of
  problems
• To a high level or detailed approach to analysis
• Foundation for many activities
• Reduces design churn
• First step for more complex analyses
• Focus is on the human part of the system

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Hierarchical Task Analysis (HTA)

• HTA is the concrete representation of the
  actions taken towards user goals and the
  logical relationship between those steps.
• Tasks are broken down into their sub-components,
  plans describe how all the pieces fit together
• Components
• Tasks (sometimes called goals or operations)
  Verb/action/qualifier
• Subtasks
• Plans
• Task details

6
Using Task Analysis Across the Organization

• Error reduction
• Training Analysis
• Documentation Design
• Systems analysis
• Others

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Error Reduction

• Use the task analysis as the basis for reviewing
  the human aspects of the system for the
  Critical Tasks
• Develop the following task details
• Performance shaping factors
• Potential error
• Hazard
• Potential consequences
• Severity
• Likelihood
• Mitigation strategy

8
Training Analysis

• Use the task analysis as the basis for
  identifying
• What could be included in a training program
• The areas where most training is required using
  DIF calculations
• Task Difficulty
• Task Frequency
• Task Importance
• Key components of competency based learning
• Competency type, competency description
• Procedural knowledge, declarative knowledge,
  strategic knowledge, attitudes
• Outcome measures
• Performance levels and required performance
  level

9
Documentation Design

• Use the task analysis to structure the
  documentation around the users goals
• Use the task analysis as a way of speeding the
  communication between systems designers and
  technical writers
• Re-use the task analysis for later product
  updates

10
System Analysis

• Use the task analysis as a communications tool
  between
• Systems architects
• Documentation
• Testing
• Marketing
• Support
• Human Factors
• Use the task analysis as the basis for
  identifying
• Areas where tasks can be simplified
• High risk operations
• Areas where tasks can be allocated to machines

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Practical Considerations

• Scope of analysis
• Depth of analysis
• Experience of the analyst time, quality of
  results
• Availability of subject matter experts
• Needs of other teams
• Criticality of the project
• Tools available

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HTA A Foundation for Safety

• To improve human reliability you need to know
• who the people are,
• what they do and
• what theyre using to accomplish their goals
• A systematic process is required to analyze
  these aspects of the system
• The results need to be easy to communicate
• The results need to be easy to re-use
• Task Analysis fulfills all of these needs.
• AND it focuses on human
  goals

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www.TaskArchitect.com
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Advanced Analysis

• HAZOP
• THERP
• GOMS
• Cognitive Task Analysis
• Cognitive Modeling
• Simulation of Human Performance

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Other Task Analysis Methods

• Task Flows
• Event Trees/Decision Trees
• State Diagrams
• Data Flow Diagrams

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Other Task Analysis Methods

• 1. Annett, J., Duncan, K. D., Stammers, R. B.,
  Gray, M. J. (1971). Task analysis.
  Department of Employment Training Information
  Paper No. 6. London, UK Her Majesty's
  Stationary Office (HMSO).
• 2. Annett, J. and Stanton, N. (Eds.) (2000) Task
  Analysis, London, Taylor Francis.
• 3. Annett, J. (2003) Hierarchical Task Analysis,
  In Holnagel, E. (2003), Handbook of
  Cognitive Task Design, Chapter 2, pp17-35.
  Mawhah NJ Lawrence Erlbaum.
• 4. Shepherd, A. (2001), Hierarchical Task
  Analysis, Taylor and Frances, London.
• 5. MIL-H-46855B