Page 253 - DMTH404_STATISTICS
P. 253
Unit 17: System Reliability
Notes
from William Grant Ireson, Clyde F. Coombs, Richard Y., Handbook of Reliability Engineering and
Management.
17.7 The Bathtub Curve and Failure Rate
Theorem 3. Consider a monotone system in which each component has the same IFR lifetime
distribution. Define
r(p) = r(p, …, p).
Then the distribution of system lifetime is IFR if
p r = (p)/r(p)
is a decreasing function of p.
Example 1: A k-out-of-n system with identical components is IFR if the individual
components are IFR.
LOVELY PROFESSIONAL UNIVERSITY 245
