MAINTAINABILITY DESIGN TECHNIQUES METRIC - AcqNotes.com

Downloaded from http://www.everyspec.com on 2011-10-29T14:56:01.DOD-HDBK-791(AM)limitations, human sensory capabilities, environmentalfactors as they affect the soldier/ machine interface, psychologicalfactors, and human error quantification areaddressed in the paragraphs that follow. The informationand data contained in MIL-HDBK-759 (Ref. 3) are notrepeated in detail in this handbook; MIL-HDBK-759 willbe referenced, and examples of the types of data will bepresented. The reader is encouraged to refer to MIL-HDBK-759 for detailed data and criteria for human factorsengineering applications.9-2 ANTHROPOMETRY (BODYMEASUREMENTS)Anthropometry—the study of human body measurements—isan important consideration in designing formaintainability because this information is necessary todesign equipment that will accommodate operators andmaintenance personnel of various sizes and shapes. Themeasurements relate to body dimensions together withthe range of motion of body members and musclestrength. The data usually are presented in terms of upperand lower percentiles. The designer should always striveto accommodate the full range of personnel designated inMIL-STD-1472 (Ref. 2), i.e., 5th through 95th percentilemale and female. When this does not appear to be feasible,the procuring activity must be notified. The reverse,designing work space and then adding the person, isusually inefficient and costly.9-2.1 SOURCES OF INFORMATIONSection 5.6 of MIL-STD-1472 (Ref. 2) and par. 2.2 ofMIL-HDBK-759 (Ref. 3) are devoted to anthropometricdata together with illustrations to explain the data. Anexample of the type of data contained in Ref. 3 is shown inFig. 9-1. (Similar data are presented for women.) Additionalanthropometric data are contained in Refs. 4through 11. Table 9-1 provides a list of laboratories thatspecialize in anthropometric research and a list of repositoriesof anthropometric data.9-2.2 MEASUREMENTSDesign and sizing measurements must insure accommodation,compatibility, operability, and maintainabilityby at least 90% of the user population (Ref. 3). Generally,design limits should be based upon a range from the5th to the 95th percentile values for critical body dimensions.For any dimension, the 5th percentile value indicatesthat 5% of the population will be equal to or smallerthan that value and 95% will be larger. Conversely, the95th percentile value indicates that 95% of the populationwill be equal to or smaller than that value and 5% will belarger. Therefore, the use of a design range from the 5th tothe 95th percentile values will theoretically accommodate90% of the required user population for that dimension. Itshould be noted that designing to accommodate the 5thfemale through the 95th percentile male accommodates90% of the combined populations (male and female)regardless of the male and female mix. This results—TABLE 9-1. SOURCES OFANTHROPOMETRIC DATANameLocationA. Primary: laboratories of anthropometry (whichspecialize in anthropometric research as well as gather alibrary of data)Aerospace Medical ResearchLaboratory, Wright-PattersonAir Force BaseUS Army Natick LaboratoriesAnthropology project. WebbAssociatesDepartment of Human Anatomy,University of NewcastleCentre d’Anthropologie Appliquee,University de ParisDepartment of Anthropology,Harvard UniversitySchool of Public Health, HarvardUniversityDayton, OHNatick, MAYellow Springs, OHNewcastle-on-Tyne,EnglandParis, FranceCambridge, MABoston, MAB. Secondary: repositories where anthropometric datamay be found (where actual anthropornetric servicesmay or may not be obtainable)US Naval Training DevicesCenterAerospace Crew EquipmentLaboratory, Naval Air EngineeringCenterHuman EngineeringLaboratoryGuggenheim Center for Aviationand Safety, HarvardUniversityInstitute for PsychologicalResearch, Tufts UniversityBiotechnology Laboratory,University of California. LosAngelesFurniture Institute ResearchAssociationUnit for Research for HumanPerformance in Industry,Welsh College of AdvancedTechnologyDepartment of Ergonomics andCybernetics, LoughboroughCollege of TechnologyInstitute of Engineering Production,University ofBirminghamBureau International duTravailOrlando, FLPhiladelphia, PAAberdeen ProvingGround, MDBoston, MAMedford, MALos Angeles, CAStevenage, Hertfordshire,EnglandCardiff, WalesLeicestershire,EnglandBirmingham, EnglandGeneva, Switzerland9-2