  Failure times of a machinery cannot always be assumed independent and
identically distributed, e.g. if after reparations the machinery is not
restored to a same-as-new condition. Framed within the renewal processes
approach, a generalization that considers exchangeable inter-arrival times is
presented. The resulting model provides a more realistic approach to capture
the dependence among events occurring at random times, while retaining much of
the tractability of the classical renewal process. Extensions of some classical
results and special cases of renewal functions are analyzed, in particular the
one corresponding to an exchangeable sequence driven by a Dirichlet process.
The proposal is tested through an estimation procedure using simulated data
sets and with an application to the reliability of hydraulic subsystems in
load-haul-dump machines.
