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A modified hybrid imperfect maintenance model (MHIM) for machine working in piecewise constant operational condition (PCOC) is proposed considering the limitation of traditional age-based hybrid imperfect maintenance model, with the assumption that failure time in different operational condition (OC) satisfies accelerated failure time model (AFTM). Method for estimating the parameters also has been provided. A policy based on optimization of average cost rate of former and current preventive maintenance intervals is presented. A numerical example is conducted to show the effectiveness of the proposed policy.

A joint model for integrating preventive maintenance (PM) with the capacitated lot sizing problem (CLSP) based on a game-theoretic framework has been proposed. Assume the production rate varies from period to period according to total lot size of each production period (PP). An imperfect PM model is established for system running with dynamic production rate, which is performed at scheduled times, and minimal repair (MR) is adopted to restore the system to work without altering hazard rate when failure happens. Considering availability reduction caused by maintenance and effect of production rate on hazard rate function of system, a Stackelberg game theory model is adopted to handle the interactive effect between production plan and PM schedule. The optimal production rate of each PP and PM sequences are obtained simultaneously. An example is studied to validate the model, also the results are discussed.

A concept of compensability is developed for free-floating flexible space robot arms. This concept is based on a methodology where end-effector behavior caused by the link flexible behavior and the satellite motion in response to the arm motion is considered as errors in the end-effector motion. The errors have to be compensated by the joint behavior. The author gives a kinematic model for n-link flexible space robot arms. Based on the results, compensability, a theorem and lemma regarding conditions for the compensability, and a measure of the compensability are derived. A new method to evaluate the capability of manipulation of the flexible space robot arms also is presented. >