Analysis Techniques For Man-Machine Systems Design

NATO UNCLASSIFIED-17- AC/243(Panel-8)TRnVolume Iin some cases that resistance is justified, citing the existence of "warehouses of useless taskanalysisinformation." Users' comments about the effectiveness and contribution of the differentanalysis techniques varied widely, from "excellent" to "worthless, inaccurate nonsense." Thecomments on any one technique also ranged widely, for example, from "very high contribution"to "poor." This suggests large differences between applications or between the experience of theusers. Only a few users commented on each technique, however, so that no specific conclusionscan be drawn. Overall it appears that the potential contribution of some categories of technique isunder-appreciated, and that some techniques require improvement27. The overall pattern of use of the techniques, illustrated in Figure 2.2, may bechanging as users adopt techniques developed more recently than others. There were largedifferences between the rankings of the techniques from one country to another. In somecountries there was a multi-project history of use of some techniques. In other countries thetechniques had been used only in the most recent projects. Several respondents indicated thattheir use of some techniques was "exploratory." Overall, the techniques favoured by mostrespondents were Function Flow Diagrams, Narrative Mission Descriptions, OperationalSequence Diagrams, and Information Flow and Processing Analysis. The techniques least usedwere State Transition Diagrams, and Siegel-Wolf Simulation (of operator task-performance).Structured requirements analysis techniques such as SADT, CORE, and RDD, were also littleused, but there were large rank order differences between user nations. Four other techniqueshad large rank order differences between nations. These were: Graphic Mission Profiles, TaskTaxonomy (for task analysis), Input: Decision: Output: Feedback Tabulations (for task analysis),and Operational Sequence Diagrams (a task analysis technique).Function Flow DiagramsNarrative Mission DescriptionsOperational Sequence DiagramsInformation Flow & Processing AnalysisTask Taxonomy 'Operator Capacity to Perform TaskTimelinesFlow Process ChartsInput:Decision:Output:Feedback TabulationsReview of Potential Operator CapabilityInformation:Action Tabulations 1Human Error AnalysisTime Budget Approach to WorkloadSubjective Workload PredictionAd-Hoc Function Allocation -Critical Task AnalysisGraphic Mission ProfilesFitts' Ust EEAttentional Demand WorkloadNetwork Models (e.g., SAINT),Weighted Comparison of H:M CapabilitySeigel-Wolf SimulationSADT/SAT/CORE/RDDState Transition Diagrams0 1 0 20 30 40 50 60Figure 2.2:Overall number of applications of 24 human engineering analysistechniques In five phases In 33 projectsNATO UNCLASSIFIED- 17 -