Availability and maintenance modeling for a two-component system with dependent failures over a finite time horizon

Abstract

This article studies the availability and optimal maintenance policy for a two-component system with failure interaction over a finite time horizon. Failure of component 1 is soft and can only be detected by inspections. Failure of component 2 is hard and self-announcing. Each hard failure acts as a shock to the first component and increases its hazard rate. Periodic and opportunistic inspections (offered by failures of component 2) are used to reveal the failure of component 1 and followed by replacement decisions. Furthermore, age-based preventive replacement is performed for component 1. Under this maintenance policy, a recursive method is developed to obtain the availability measure of component 1. Furthermore, the total maintenance cost of component 1 over a finite time horizon is analyzed. The objective is to find the optimal maintenance policy for component 1 such that the expected total cost is minimized. A case study on electrical distribution system is provided to validate the effectiveness of the adopted approach.

An improved opportunistic group replacement maintenance strategy for wind turbines

“…9 Several literatures studied the opportunistic maintenance strategy for wind turbines. An optimal maintenance strategy for a two-component system was studied in REF, 10 and the failures of component 2 offered the periodic and opportunistic inspections for the failure of component 1. An optimal proactive age-based group maintenance strategy was proposed in Ref.…”

Preventive maintenance policy of single‐unit systems based on shot‐noise process

“…Such models concentrate on the impact of external shocks on the increment of degradation amounts. Common stochastic processes describing degradation behaviors include gamma process, Wiener process, general path model, and inverse Gaussian process, eg, and arrival processes of random shocks are generally modeled by Poisson process, eg, In this regard, Song et al considered reliability analysis of multiple‐component series systems subject to internal degradation and external shocks with dependent shock effects; Liu et al studied the condition‐based maintenance for continuously monitored degrading systems operating in dynamic environment; Rafiee et al investigated the reliability analysis and condition‐based maintenance for failure processes with degradation‐dependent hard failure threshold.…”

“…Such models concentrate on the impact of external shocks on the increment of degradation amounts. Common stochastic processes describing degradation behaviors include gamma process, Wiener process, general path model, and inverse Gaussian Nomenclature: NHPP, Nonhomogeneous Poisson process; WTS, Wind turbine system; T, Interval of periodic preventive repair; N s (t), Number of shocks that has arrived by time t; λ s (t), Arrival rate of random shocks; Λ s (t), Cumulative arrival rate of shocks; λ h (t), System hazard rate in a baseline environment; Λ h (t), Cumulative hazard rate in a baseline environment; Y, Jump on the hazard rate when a shock occurs; f Y (y), Probability density function of Y; λ(t), Random hazard rate in the presence of shocks; X, Random time to system failure; N s (u, v), Number of shocks in time interval [u, v); S ki , Arrival time of the ith shock in [(k − 1)T, kT); R(t), Reliability of X at time t; f (t), Probability density function of X at time t; K, Number of preventive repairs in a renewal cycle; N s , Number of shocks in a renewal cycle; c m , Economic loss caused by a shock; c r , Cost of a preventive repair; c p , Cost of a preventive replacement of the system; c c , Cost of a corrective replacement of the system; n, Preventive replacement limit; C, Total maintenance cost in a renewal cycle; S, Length of a renewal cycle; w(n, T), Average long-run cost rate as a function of n and T process, eg, [8][9][10] and arrival processes of random shocks are generally modeled by Poisson process, eg, 11,12 In this regard, Song et al 13 considered reliability analysis of multiple-component series systems subject to internal degradation and external shocks with dependent shock effects; Liu et al 14 studied the condition-based maintenance for continuously monitored degrading systems operating in dynamic environment; Rafiee et al 15 investigated the reliability analysis and condition-based maintenance for failure processes with degradation-dependent hard failure threshold.…”

Reliability evaluation and opportunistic maintenance policy based on a novel delay time model

“…Cavalcante et al proposed a general inspection and opportunistic replacement policy for one‐component systems of variable quality. Qiu et al considered an opportunistic inspection model for a two‐unit system subject to periodic and random inspection which is carried out at the completion of each mission to take advantage of the idle periods between missions and reduce the downtime caused by inspections. Li et al proposed an age‐based replacement strategy considering production waits arriving according to homogenous Poisson process.…”

“…Preventive maintenance can timely detect and remove pending failures and plays a key role in improving system reliability and reducing operational cost, eg, Peng et al and Pandey et al 24,25 However, preventive maintenance actions require the shutdown of systems, causing expensive downtime costs. On the other hand, during system operating process, unscheduled shutdown may arise due to unavoidable external factors such as harsh weather or insufficient raw materials, which offers extra opportunities to perform maintenance actions, eg, Nakagawa 33 considered an opportunistic inspection model for a two-unit system subject to periodic and random inspection which is carried out at the completion of each mission to take advantage of the idle periods between missions and reduce the downtime caused by inspections. Li et al 34,35 proposed an age-based replacement strategy considering production waits arriving according to homogenous Poisson process.…”