MAINTAINABILITY DESIGN TECHNIQUES METRIC - AcqNotes.com

Downloaded from http://www.everyspec.com on 2011-10-29T14:56:01.DOD-HDBK-791(AM)tire sizes, and common materials for uniforms arid canvascoverings.Standardization is mandated by DoD Directive No.4120.3 (Ref. 1) and implemented by DoD Intruction No.4120.19(Ref. 2) (see par. 3-5); however, the main impetusderives from the willingness of engineers and programmanagers to use existing equipment to satisfy their particularneed.3-2.1 DESIGN GOALS AND PRINCIPLESStandardization was previously defined as a designfeature for restricting to a minimum the variety of partsthat will meet the majority of the hardware requirementsof the system. According), it is important that maintainabilityengineers strive for the design of assemblies andcomponents for a given system that are physically andfunctionally interchangeable with other like assembliesand components of the system. The importance of standardization,a major consideration of maintainabilitydesign, translates into achieving the following primarygoals:1. Minimizing both the acquisition and supportcosts of a system2. Increasing the availability of mission-essentialitems3. Reducing training requirements both in numberof personnel and the level of skill required4. Reducing inventories of repair parts and theirassociated documentation.In any attempt to achieve standardization, the followingprinciples must be carefully considered:1. Make maximum use of all common parts andassemblies.2. Reduce to a minimum the variety of assembliesand parts required, and, in doing so, make certain that thebasic types area. Used consistently for each applicationb. Compatible with existing uses and practices.3. Reduce to a minimum, by careful study of thesimplification thus attained. the problems of supply, storage,and stocking.4. Simplify practices, by the same means. in thecoding and numbering of parts.5. Make maximum use of “off-the-shelf” components,tools, and test equipment.3-3 INTERCHANGEABILITY3-3.1 GENERAL3-2.2 ADVANTAGESWhen standardization is carried to the practical maximumin system design. certain major advantages aregained by the support activities required for the completedsystem, i.e.,1. Both the types and quantities of repair parts normallyare reduced and required parts are usually at available;this reduces overall support costs.3-2