A quasi-optimal inspection strategy for leased equipment.

This paper presents a quasi-optimal inspection policy for equipment that is leased for a given period and whose failures can be detected only through inspections. Maintenance including inspections and replacements is entrusted to the lessor. Whenever inspection reveals that the equipment is in failed state, it is replaced (or restored to a state as good as new). In case the average downtime between failures and their detection exceeds a contractual pre-specified duration, a penalty is incurred by the lessor. The proposed mathematical model and numerical algorithm allow finding a quasi-optimal sequence of inspection instants (θ₁*, θ₂*, ... , θ_N*) which minimises the expected total cost incurred by the lessor over the lease period L. A numerical example is presented and the obtained results are discussed. We investigate numerically the effect of the variation of the downtime penalty cost, the inspection cost, the lease period length, and the equipment reliability on the quasi-optimal inspection policy to be adopted by the lessor. [ABSTRACT FROM AUTHOR]