Downloaded from https://www.everyspec.com AMCP 70&100 CHAPTER.7 ,ACCELERATED TESTING LIST OF SYMBOLS 741 INTHODUCTION"I A a acceleration factor Accelerated testing Is a very loosely defined concept; atte~mpts to make If rigorous gener- a incremental acceleration factor ally run Into difficulties. Loo 86lY speaking, Cumultivedistrbutin funtionaccelerated testing started whqn i6mii~o'e . ..
* Cdf uuaiedstiuinfnto said, "Let's shoot the Juice toit atid see what happens." This mieant, roughly, "Let's d *factor for Kolmogorov-Smirnov treat it worse than we ex~pect it to be treated test in ordinar practice and then see what hap- pens," One difficulty is that treating-it- 1, b a state of a system worse does not always meani "shooting theA equialen stae ofa sytemjuice to it". For example, electrical con- G a quivlentstae ofa sytemtacts behave better as voltage and current are increased (up to a point) and some . alife warmth may improve matters for electronic equipment by helping to reduce the mois- MtF -Median time to F~ailure ture problem. P 10 mlife:
10% will fail bef~or that time Accelerated testing in this qualitative sense is something that anyone can do and S implies the wordl "statistical(ly)", that everyone does. There is a reasonably or Implies that the technical firm qualitative foundation for much of It. statistical definition is Intended It Is in the quantitative interpretation that rather than the ordinary dictionary troubles begin. These qualitative and quanti- definition tative uses of accelerated testing can con- t *timeveniently be put into four classes: 1.
Qualitative - to se# what kind, of T *absolute temperature (also a sub- failures are generated"'and to decide then if ,\script); total test time a modification is worthwhile a random variable 2. Qualitative - to got a rough, quick Idea of whether or not something can stand *failure rate the gaff r -transformed time * Implies an unknown parameter *Lazp portioni or this chapter mer adapted haom Reft 2 and 3 - they arn similar uOwe the accelersatd ~~ teatn portion or Ref, 2 was written by the author of implies a point estimate Ref..