(A) study on preventive maintenance

학위논문(석사) - 한국과학기술원 : 산업공학과, 1977.2, [ vi, 91 p. ]In this thesis, an attempt is made to examine whether the ROK Air Force maintenance programs, that are currently being utilized on a borrowed basis from the US Air Force, are suitable to its existing environment. This study also provides guidelines for the maintenance managers and their personnel in; a. application of periodic preventive maintenance models to their operations, and b. necessary modification of the current maintenance programs to improve their effectiveness. Three relatively simple but critical units are chosen for determining the optimal preventive maintenance intervals applying simple age preventive maintenance scheduling model. The results of this study indicates that the current maintenance programs are inadequate to their existing environment and need to be modified to improve the maintenance effectiveness. As the preventive maintenance consumes vast amount of national resources and is vital to the mission accomplishment of national defense, more extensive reevaluations of the current programs are suggested so as to obtain the maximum effectiveness of the preventive maintenance programs in ROK Air Force operations.한국과학기술원 : 산업공학과

裝備群運用을 위한 整備支援體系의 分析및 最適設計

학위논문(박사) - 한국과학기술원 : 산업공학과, 1980.8, [ iv, 112 p. ]This study is concerned with a military activity operating fleet of multiple units essential for national defense in an operational base and repair depot combination. Analysis of the fleet operations is necessary not only to maintain effective national security but also to efficiently utilize the defense funds available. Interactions of major factors in fleet operations are modeled in the framework of a closed queueing network system with a finite number of units assigned to the fleet. The factors affecting the fleet operations, such as unit``s characteristics and population, operational policies and constitution of repair depot including specialized repair facilities and spare module inventory, are intended to approximate the real situations more closely than other related works in the literature. A recursive computing algorithm is developed to evaluate the effect of operational policies and investment decisions for repair depot supportability on fleet availability. Fleet availability is an important part of operational effectiveness for such fleet deployed at forward areas of conflict and can be measured as average fraction of units operable at a random instant. In addition, this study provides a resource allocation program for improving the fleet availability when a limited amount of funds is available. The program focuses on allocating the funds available to multiple repair and inventory stations in the repair depot competing for their use. The optimization problem on hand is a mixed integer-nonlinear programming problem. Since an adequate programming algorithm has not yet been developed in solving the problem, heuristic methods based on gradient techniques are employed. Approximate solutions, although not optimal, can be obtained efficiently by the method.한국과학기술원 : 산업공학과