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Task Analysis: A Foundation for Safety. Nov.19, 2004 Jon Stuart, Ph. D. Presentation Overview. What is task analysis? The benefits Critical components of task analysis – example Using task analysis across the organization Practical considerations. Task Analysis.
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Task Analysis: A Foundation for Safety Nov.19, 2004 Jon Stuart, Ph. D
Presentation Overview • What is task analysis? • The benefits • Critical components of task analysis – example • Using task analysis across the organization • Practical considerations Jon Stuart, Ph.D
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 Jon Stuart, Ph.D
Benefits of Using Task Analysis • 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 Jon Stuart, Ph.D
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 Jon Stuart, Ph.D
Using Task Analysis Across the Organization • Error reduction • Training Analysis • Documentation Design • Systems analysis • Others … Jon Stuart, Ph.D
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 Jon Stuart, Ph.D
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 Jon Stuart, Ph.D
Documentation Design • 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 Jon Stuart, Ph.D
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 Jon Stuart, Ph.D
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 Jon Stuart, Ph.D
HTA – A Foundation for Safety • 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 behaviour Jon Stuart, Ph.D
www.TaskArchitect.com Jon Stuart, Ph.D
Advanced Analysis • HAZOP • THERP • GOMS • Cognitive Task Analysis • Cognitive Modeling • Simulation of Human Performance Jon Stuart, Ph.D
Other “Task Analysis” Methods • Task Flows • Event Trees/Decision Trees • State Diagrams • Data Flow Diagrams Jon Stuart, Ph.D
Further Reading • 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 Jon Stuart, Ph.D