Accession Number : AD0690876

Title :   GAMMA AND WEIBULL LIFE-QUALITY PLOTS,

Corporate Author : NEW YORK UNIV BRONX DEPT OF INDUSTRIAL ENGINEERING AND OPERATIONS RESEARCH

Personal Author(s) : Kao,John H. K.

Report Date : 15 MAR 1968

Pagination or Media Count : 27

Abstract : The life quality of an industrial product can be characterized by its lifelength distribution. Given 'Good' failure data, the simplest way to estimate the life-length distribution is by the probability plot. This paper presents two such plots: gamma and Weibull (Form 2) probability plots which represent two theories of failures. The gamma distribution arises from the rope (or parallel-structure) failure model while the Weibull distribution comes from the chain (or series-structured) failure model. In rope model, the item fails when the last or the strongest strand of the rope fails whereas in the chain model, the item fails when the first or the weakest link of the chain fails. Scales which facilitate quick estimates for the mean and standard deviation of the lifelength distribution are also presented along with the plots. (Author)

Descriptors :   (*RELIABILITY, LIFE EXPECTANCY), (*STATISTICAL DISTRIBUTIONS, LIFE EXPECTANCY), PROBABILITY DENSITY FUNCTIONS, FAILURE(MECHANICS), FAILURE(ELECTRONICS), MAINTENANCE, SPECIAL FUNCTIONS(MATHEMATICAL)

Subject Categories : Operations Research
      Mfg & Industrial Eng & Control of Product Sys

Distribution Statement : APPROVED FOR PUBLIC RELEASE