Nov.19, 2004

Jon Stuart, Ph. D.

Task Analysis: A Foundation for Safety

04/18/23 Jon Stuart, Ph.D 2

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

Presentation Overview

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• 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

Task Analysis

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•Systematic (thorough)•Easy to learn

Demystifies human behavior; don’t 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

Benefits of Using Task Analysis

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• 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

Hierarchical Task Analysis (HTA)

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

Using Task Analysis Across the Organization

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• 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

Error Reduction

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•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

Training Analysis

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• Use the task analysis to structure the documentation around the user’s 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

Documentation Design

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• 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

System Analysis

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• 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

Practical Considerations

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• To improve human reliability you need to know who the people are, what they do and what they’re 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

HTA – A Foundation for Safety

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www.TaskArchitect.com

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

Advanced Analysis

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

Other “Task Analysis” Methods

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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

Other “Task Analysis” Methods