Modeling failures of repairable systems under "worse than old" assumption

The objective of the work is to model the failure process of a repairable system under "worse than old", or harmful repairs, assumption. The proposed model is founded on the counting process probabilistic approach and interprets harmful repairs as the accumulation of failures on the same system. The explicit form of likelihood function is given. Fixed and time-varying covariates are taken into account. Monte-Carlo simulations are carried out to asses the quality of the MLE. The method of data generation is detailed