Likelihood ratio test for homogeneity of steady-state availabilities against order restrictions

The likelihood ratio test (LRT) is considered for comparing the steady-state availabilities among several system units within order restrictions. Assuming exponential distributions for failure and repair times, we discuss finding the maximum likelihood estimates of the order restricted parameters, and then derive the asymptotic null distribution of the likelihood ratio test statistic. The test based on this limiting distribution shows fairly good performances even with very small sample sizes. This fact will be investigated through a power analysis at various parameter configurations in the alternative hypothesis. (C) 2000 Published by Elsevier Science B.V. All rights reserved.