Analysis Techniques For Man-Machine Systems Design

NATO UNCLASSIFIED"AC/243(Panel-8)TR17- 38 -Volume 1goals is to run a SAINT simulation, then the analysis should generate a description of the tasknetwork from Operational Sequence Diagrams (OSDs) or a similar technique.3.2.4 Related techniques55. As indicated in Figure 3.1, the classes of analysis are related to one another.Similarly, within each class, techniques tend to be related. For, example two techniques forfunction analysis, Sequence and Timing Diagrams (SATs) and Function Flow Diagrams (FFDs),are related; in task analysis, Operational Sequence Diagrams (OSDs) are developments of FlowProcess Charts with symbols for operator actions added.56. In reviewing the various human engineering techniques, one objective was toexamine their compatibility with other engineering processes. Several of the techniques reviewedare related to, or used for, systems engineering analyses. As might be expected, most of thosetechniques are used in the early stages of analysis. Such common techniques include Missionand Scenario Analysis, FFDs, SATs, Structured Analysis and Design Technique (SADT), StateTransition Diagrams (STDs), Petri Nets, and Behaviour Graphs. The latter is an integral part of asystems engineering approach called Requirements Driven Development tAlford. 1989).57. None of the human engineering techniques used for the function allocation stage ofanalvsis is used for mainstream systems engineering studies, although the basic technique ofcomparing the capabilities of different design solutions is by no means unique to humanengineering. It is tempting to conclude that human engineering specialists are the only onesconcerned with the systematic allocation of functions to humans, and that other engineeringspecialities do it by default, through the selection of hardware and software (Chapanis, 1970;Meister, 1985). However, the Requirements Allocation Sheet, described in some systemsengineering texts (Defense Systems Management College, 1990) is one technique whichcombines the functional allocations for hardware, software and personnel by identifying subsystemand personnel performance requirements.58. Several techniques for task analysis are common to other engineering analyses.These include Time Lines, Flow Process Charts, Decision Tables, Systems Analysis byIntegrated Networks of Tasks (SAINT), and Error Analysis. In the area of interface andworkspace design, only one of the three techniques reviewed, Critical Design Requirements, canbe said to be used for other engineering analyses.59. Overall, it can be concluded that there is a fairly high level of commonality betweenhuman engineering and systems engineering analyses. Fifteen out of the thirty-one techniquesreviewed are used for other engineering analyses, including the two most frequently used humanengineering analyses (Function Flow Diagrams and Narrative Mission Descriptions). Thisshould facilitate communication between human engineering specialists and other members of thedesign/development team. Despite the use of common techniques, however, different specialitiesconduct their analyses from different viewpoints. For example, systems engineering activitiesmay analyse scenarios, or complete functional decompositions, without including the humanoperator (Beevis, 1987). Thus the human engineer may have to revise or modify analysesconducted by other specialities in order to highlight human factors in system or equipmentdesign.3.2.5 Resources required60. Most of the techniques reviewed can be conducted using simple "paper and pencil"resources. For only five of the techniques reviewed was the use of a computer mandatory. PetriNets and Behaviour Graphs require Computer Aided Software Engineering (CASE) tools toA