Abstract: An example method includes calculating a first probability that an unretired representative aircraft will have a future service lifetime that is no less than a first service lifetime of a first retired aircraft, calculating a second probability that the unretired representative aircraft will have a future service lifetime that is no less than a second service lifetime of a second unretired aircraft, based on (i) the first probability, (ii) the second probability, (iii) a first operation history of the first retired aircraft, and (iv) a second operation history of the second unretired aircraft, generating a theoretical hazard function that is dependent on a current service lifetime of the unretired representative aircraft and dependent on an operation history of the unretired representative aircraft, and based on (i) the theoretical hazard function, (ii) the second service lifetime, and (iii) the second operation history, calculating a quantity of a component to maintain.