Preventive Replacement Policies with Aging Failure and Third-part Damage

In general, corrosions, degrading the mechanical strength of pipelines gradually with its age in a stochastic way, is the predominant cause of pipeline leaks. In addition, the third-part damage is the leading cause of pipeline ruptures, which occurs randomly in a statistical sense. Naturally, corrective replacement (CR) is done immediately when the pipeline is subjected to a random failure. To reduce the failure probabilities, preventive replacement (PR) policies are scheduled to meet the failure due to aging and the third-part damage. We model three PR policies, using the renewal theory in reliability, and obtain their optimal solutions analytically to minimize respective replacement cost rates. Finally, numerical examples are given to compare these policies.