This paper is concerned with the maintainability task selection procedure and the test
methods for maintainability verification. Two basic approaches, stratification and simple random
sampling, are introduced and illustrated through an example. Also suggested and illustrated are
test methods for the mean corrective/predictive maintenance time as well as the mean
corrective/predictive maintenance time and the maximum value of a percentile of maintenance
time. This paper is expected to contribute to the understanding of domestic enterprises for the
maintainability verification concept and test methods.