Optimal Trivariate Replacement Policies for a Deteriorating System

An Imperfect Repair Model with Delayed Repair under Replacement and Repair Thresholds

“…In other words, based on the optimal policy, the replacement occurs when the working time reaches 12.0509 for the first time. given by Equation (17). We can find that 1 1 ( )…”

“…Let λ = 80, η = 15, a = 1.05, b = 0.95, p = 0.45, q = 0.55, c f = 10, c d = 50, c r = 1800, τ 2 = 20. Figure 2 is the plot of the long-run average cost rate C 1 (τ 1 ) given by Equation (17). It can be found that C 1 (τ 1 ) decreases in the interval [0, 12.0509] and increases in the interval [12.0509, 20].…”

“….) into Equation (17). Furthermore, if the system after maintenance degrades successively, i.e., p i = 0, i = 1, 2, .…”

“…Case 3. τ * 1 = τ 2 . Let λ = 120, η = 15, a = 1.05, b = 0.95, p = 0.45, q = 0.55, c f = 10, c d = 50, c r = 300, τ 2 = 20; Figure 4 is the plot of the long-run average cost function C 1 (τ 1 ) which is given by Equation (17). We can find that C 1 (τ 1 ) decreases in the interval [0, 20], which means that the optimal τ * 1 = 20, and the minimum of the long-run average cost rate is C 1 (20) = 1.8842.…”

“…Chang et al [16] considered a bivariate replacement policy (n, T) based on the life age and the number of Type-I and Type-II failures. Sheu et al [17] extended the bivariate replacement policy (T, N) to two trivariate replacement policies (K, N, T) and (N, S, T), in which K is a tolerance limit of failure and S is the lower working age.…”