Application of Spearman’s Method for the Analysis of the Causes of Long-Term Post-Failure Downtime of City Buses

The aim of this study was to analyze the impact categories bus downtime caused by necessity their repair on availability indicator. A retrospective covering 12 years operation carried using selected municipal transport company as an example. share in total time vehicle analyzed. Spearman’s rank correlation coefficient used for analysis. research covered seven makes and types buses six downtime. ranking developed according criterion statistical dispersion stoppage a measure unpredictability. It shown that categorized unavailability strongly dependent loosely age buses. In practical applications, test results may be useful improving fleet maintenance processes, selecting make new or development models safety margin availability.