SMALL SAMPLE ACCEPTANCE SAMPLING TABLES USING B10 RELIABLE LIFE AND B10 HAZARD RATE CRITERIA BASED ON THE WEIBULL DISTRIBUTION.
Abstract
Acceptance criteria are established for B sub 10 reliable life and B sub 10 hazard (instantaneous failure) rate, assuming that a Weibull failure time distribution with shape parameter 0.6 = or < beta = or < 2.0 applies. B sub 10 reliable life is the time at which 90% of all items are expected to be still in operation, and B sub 10 hazard rate is the number of failures per unit - time (hours, cycles, etc) expected at B sub 10 life. Acceptance sampling plans based on the binomial probability distribution have been developed, for each criterion, using sample sizes of 2 = or < n = or < 50, and acceptance numbers of 0 = or < c = or < n-1, c = or < 8, to assure, with minimum confidence of 90% and/or 95% the acceptance of lots for which the survival probability is 90% or more, at some specified time, t. Comparisons between B sub 10 reliable life and B 10 hazard rate indicate that either may be used with equal facility as acceptance sampling criteria. However, B sub 10 hazard rate estimated would be most appropriate for establishing correction factors to compare basic environmental test results, with results obtained under other than basic conditions. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1968
- Accession Number
- AD0839460
Entities
People
- David W Taylor
- Donald J. Fisk