Citation

Mann NR, Saunders SC. Biometrika 1969; 56(3): 615-625.

Copyright

(Copyright © 1969, Biometrika Trust, Publisher Oxford University Press)

DOI

10.1093/biomet/56.3.615

PMID

unavailable

Abstract

A two-parameter Weibull model with neither parameter known is assumed for failure time. A value is specified for the probability that no failures, in a lot of identically distributed components yet to be manufactured, will occur before the expiration of the warranty period. The warranty period, which must satisfy an assurance criterion at the prescribed probability level regardless of the true parameter values within the distribution, is to be calculated from a small preliminary sample of life lengths. An expression for the warranty period is derived as a function of the ordered observations and is determined only by the lot size, the sample, size and the prescribed assurance level.