Springer Series in Reliability Engineering



Maintenance involves preventive (planned) and
unplanned actions carried out to
retain a system at or restore it to an acceptable operating condition. Optimal
maintenance policies aim to provide optimum system reliability and safety
performance at the lowest possible maintenance costs. Proper maintenance
techniques have been emphasized due to increased safety and reliability
requirements of systems, increased complexity, and rising costs of material and
labor (Sheriff and Smith 1981). For some systems, such as aircraft, submarines,
military systems, aerospace systems, it is extremely important to avoid failure
during actual operation because it is dangerous and disastrous. One important
research area in reliability engineering is the study of various maintenance policies
in order to improve system reliability, to prevent the occurrence of system failure,
and to reduce maintenance costs (Pham and Wang 1996).
In the past several decades, maintenance, replacement and