PARAMETRIC MULTIPLICATIVE INTENSITIES MODELS FITTED TO BUS MOTOR FAILURE DATA

Classes of two- and three-parameter multiplicative intensities models are presented. These have the advantage that they can be simply fitted by standard software. The two-parameter models include the Weibull an d extreme value models, whereas the three-parameter models can have ba thtub-shaped forms. The bus motor failure data are reanalysed to show that all five failures of the 191 buses can be adequately described by the same two-parameter multiplicative intensity model based on the sq uared logarithm of distance travelled in service since previous repair . This is a new member of the multiplicative intensity family, based o n the squared logarithm of distance, or of time for survival data.