9500289 Okogbaa This research project focuses on the problem of preventive maintenance for complex systems under transient state. The goal is to develop models and algorithms useful for operating and characterizing a preventive maintenance system. In particular, the following objectives are pursued to realize the set goal: (1) develop techniques for characterizing failures and renewal process distributions for complex multi-unit systems with emphasis on systems transient phenomenon and the aging process; (2) construct analytical models based on transient formulation using renewal and semi-regenerative processes with maintenance cost consideration; (3) explore the convexity of the resulting transcendental functions using optimization techniques and heuristics with the aim of minimizing maintenance costs; (4) develop a set of cost boundary indices to assist in analyzing the reasonableness and sensitivity of the cost options; and (5) test and verify the sensitivity and endurance of the models and the algorithms using discrete event simulation. Actual industrial data will be used in the testing and validation of the models. Many man-made systems today are characterized by mechanical, electrical, and electronic components that are highly integrated to produce a working system. With high integration also comes increased vulnerability to failure due to the malfunctioning of individual or groups of components in the system. A reliable and workable preventive maintenance program ensures a high run time for machines and a more productive system. Increased productivity is essential for economic competitiveness both for a company and to a nation. If successful, the tools developed as part of this research will contribute to the realization of effective preventive maintenance programs. Given the critical need to keep systems running and prevent catastrophic failures, research in this area has much to offer to the industrial world.
