Citation

Shima E, Nakagawa T. Reliab. Eng. 1984; 7(3): 123-132.

Copyright

(Copyright © 1984, Elsevier Publishing)

DOI

10.1016/0143-8174(84)90011-8

PMID

unavailable

Abstract

Almost all machines install a protective device to protect against unexpected internal or external shocks. Such a device should be inspected often to check whether it is working. A machine with a protective device which is inspected at predetermined 'check times' is considered. Using the usual calculus method of probability, two expected costs are derived. When the failure time of the device is exponential, optimum checking intervals to minimize the expected costs are obtained and numerical examples are given.