An Truong Ba Huy creator Trung Luong Huynh Chairperson Voratas Kachitvichyanukul Examination Committee Pisut Koomsap Examination Committee Asian Institute of Technology Fellowship Scholarship donor text series technical report th Pathum Thani, Thailand Asian Institute of Technology 2008 continuing eng 132 p. : ill. This thesis studies the selective maintenance policy based on the ages of the components in the system. After a fixed operation time period, the system will be maintained in a short period before the next operation cycle. In the fixed maintenance period, the replacement with identical item, the replacement with upgraded item, the rehabilitation or doing nothing actions will be chosen for each component of the system. In operation period, if the machines fail, they will be minimally repaired immediately to restore the working condition. The mathematical models are proposed to maximize the availability and the reliability of the system under the constraints of maintenance time and budget. The models are developed for the serial system, the parallel system and the serial-parallel system. The illustrating examples of the availability-maximization models are solved by using Lingo program and compared with the results coming from @Risk Optimizer program. The numerical examples of reliability-maximization models are solved by using @Risk Optimizer program. This research also extends the study on the multi-cycle selective maintenance policy with the maximin model and cost-minimization model. In these models, the system is considered in a planning horizon with a predefined number of cycles and the budget is set for all cycles. The numerical examples are also investigated by using @Risk Optimizer program. Submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Industrial Engineering and Management, School of Engineering and Technology Thesis (M.Eng.) - Asian Institute of Technology, 2008 Machinery Maintenance and repair Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B03237 http://203.159.5.9/ait-thesis/detail.php?q=B03237 100807 20260817161825.0