MAP-01-011 HFI Technical Guide - Human Factors Integration ...

Annex 3 – HF Techniques, Methods and ToolsA3.4 Task Analysis TechniquesTask analysis techniques are used to understand and represent human andsystem performance in a particular task or scenario and the task analysis oftask(s) is the next natural step after the data collection process. However taskanalysis is both a technique-specific and a generic term.When used in the specific sense, it relates to techniques that analyse a set ofexisting, or at least pre-defined, user, operator or maintainer tasks and activitiesas part of the operation of a socio-technical system. Through direct or indirectobservation, interaction with operators and maintainers and appropriate datarecording, human tasks are identified, measured, analysed, decomposed andinterrelated to a level of granularity that suits the analyst’s purpose.When used in the generic sense, the term task analysis is often used to describea set of related techniques that include task decomposition, task description, andtask synthesis, where sets of tasks are assembled to form higher order taskdescriptors.HF practitioners use a range of different techniques depending on the goal of thetask analysis, however some of the more commonly used techniques include:• Hierarchical Task Analysis (HTA)• Tabular Task Analysis (TTA)• Task Decomposition• Verbal Protocol Analysis• Timeline Analysis• Critical Path Analysis (CPA)• Goals, Operators, Methods and Selection Rules (GOMS)• Keystroke Level Model (KLM)It should be noted that the concept of task analysis has evolved and nowencompasses the cognitive, team and decision-making aspects of tasks andwork analysis and these are covered later in this annex, see under Sect A3.5Cognitive Task Analysis Techniques, Sect A3.6 Mental Workload AssessmentTechniques, Sect A3.8 Team Design Techniques and Sect A3.9 TeamPerformance Analysis TechniquesThe use of Task Analysis techniques can be extremely resource and timeconsumingand therefore two key tenets to be considered when conducting taskanalysis are:• Task Analysis should be applied where necessary to obtain data that isknown to be required and does not already exist. A search for legacysystem task analyses that may provide a starting point is recommended.• Task Analysis needs only to be conducted to the required level ofgranularity. In many cases, a high-level (and therefore less resourceMay 2006 Page A3-27 Issue 4