... the operation of gas turbines. The time to failure of gas turbines is modeled using Weibull distribution. Findings – The total risk is estimated considering replacement cost, repair cost, operation cost, risk of failure and turbine remaining value after a specified period of time. Originality/value...

...M.N. Azaiez We formulate a multi‐attribute decision model for preventive replacement of a “magnetic sealing head” in a soft‐drink producing factory in the Kingdom of Saudi Arabia. In case of failure of this part, the opportunity cost (for production losses) is very important, as the entire...

...T. Dohi; A. Ashioka; S. Osaki; N. Kaio In this paper, we consider a repair‐time limit replacement problem with imperfect repair and develop a graphical method to determine the optimal repair‐time limit which minimizes the expected total discounted cost over an infinite time horizon. The method...

...Won Young Yun; Chung Hyeon Choi An optimization problem to obtain the optimal replacement interval is studied. The system is minimally repaired at failure and is replaced by a new one at age T. The model assumes that the time horizon associated with the number of replacements is random...

...Jui‐Hsiang Chiang; John Yuan A continuous‐time multi‐state Markovian deteriorating system subject to aging and fatal shocks under continuous inspection is investigated in this paper. An action is chosen from {do‐nothing, repair, replace} upon each state x transited from the resulting state...

..., the expected discounted costs over an unbounded horizon; and third, the expected equivalent average costs per unit time. Illustrates the maintenance model by determining optimal age replacement and lifecycle costing policies, which optimally balance both the failure cost against the preventive repair cost...

... the most cost‐effective replacement vibration level, when a vibration‐based maintenance is implemented, i.e. when the available data are mainly condition‐based replacement. This method is based on the concept of the total time on test, TTT‐plot. The use of this method is explained by three examples...

...P.A. Scarf; O. Bouamra A replacement model over two cycles, with decision variables based on age at replacement of the current fleet and size of the new fleet is considered. In order to consider both age at replacement and fleet size, the concept of penalty cost for unmet demand is introduced...

...Wei‐peng Liao; John Yuan Notes that the so‐called age replacement model was first proposed to determine the optimum age limit at which the system is replaced after installation. It was then extended by further assuming that the one‐unit system is supported by a buffer which stores only one spare...

...A.B.M. Zohrul Kabir Presents a case study on overhaul/replacement policy for a fleet of buses owned by a Saudi Arabian transport company. Data on overhaul and operational costs for two types of bus engines have been collected and analysed by standard statistical procedures to establish...

...Rakesh Gupta; S.Z. Mumtaz Deals with the stochastic analysis of a two identical unit cold standby system model with repair and replacement policies. Taking the bivariate exponential distribution of failure and repair times and using the regenerative point technique, various measures of system...