Analysis Techniques For Man-Machine Systems Design

NATO UJNCLASS IFTEDACt243(Panei-8)TRW7- 8 -Volume 1tasks which may require close examination by field trials, simulation, experiments ormathematical modelling. As reported by Lovesey (Fig. 1.7), the estimates of a system'seffectiveness are degraded successively from concept through field trials and initial introductioninto service to routine and wartime operations. Appropriate use of human engineering in theoverall design of a system will help to produce designs that are more compatible with thecapabilities and limitations of personnel, thereby reducing the inevitable degradation inperformance from system concept to the combat environment.TMACHINE£ .. .. /.FACTORS> 81"A f s °.-u cJ r~~~w~gJ0 e tc °1 .tWLow|-coand ptoet cntHUMANSore WM. fatigue. sleepls iLow [ FACTORS /PROGRESSION OF SYSTEM DEVELOPMENT AND USEFigure 1.7: Some factors causing operational degradation (after Lovesey, 1987)1.3 HUMAN ENGINEER{ING TECHNIQUES16. Table 1.1 gives an overview of the main human engineering design steps in thesystems development process (U.S. NAVSEA, 1990). These parallel the essentiai steps insystems engineering. When a system or equipment is being modified, without this beingclassified as a mid-life improvement, some of the early steps are not carried out fully, or may beomitted. The sequence of human engineering analyses follows the same general pattern assystems engineering, including: mission analysis, function analysis, function allocation, taskanalysis, and performance prediction. This human engineering process was recommended foradoption in the NATO Land Operations Study (NATO DRG, 1981). The sequence of analyseshas been formalize d in NATO STANAG 3994 Al (Application of human engineering to advancedaircraft systems) (NATO MAS, 1991). Some of the steps associated with human engineeringanalyses have been documented by NATO Naval Armaments Group Information ExchangeGroup 6, Sub-Group (IEG-6, 199 1).17. As noted in para. 1 1, a concept of the system may well have been established prior toany analysis being undertaken. Because of this, many designers and engineers have difficultyunderstanding the need for analysing systems from a functional viewpoint. The importance ofsuch an approachis that it permits engineers and designers to look at the system concept in newways, by identifying the functions which must be performed, rather than by identifying theNATO RNCSASSIFED