Abstract
The three principal types of replacement policies discussed in the literature are age replacement (ARP), block replacement (BRP), proposed by R. Barlow and F. Proschan, and the non-preventive approach known as failure replacement (FRP) . The former two types are widely used as the preventive replacement policies.
The objective of this paper is to provide a simple rule for choosing the least costly of the three policies for any possible values of the planned replacement cost. As the distribution of the life times of units, we adopt the Weibull probability model with one parameter, i.e., the shape parameter. In particular, we stress on the relations between the three policies and the shape parameter.
In order to obtain the relations, it is necessary to solve the Renewal function, and then we obtain its results on the Weibull model due to the numerical methods. According to the results, the simple rule for choosing is given under the condition of variation of the shape parameter. Finally, the usefulness of the rule is shown by illustrating for the field data of the marine use mechanical units.
