Preventive Maintenance for Complex Systems Under Transient State

9500289 Okogbaa本研究项目致力于复杂系统在暂态下的预防性维护问题。其目标是开发可用于操作和表征预防性维护系统的模型和算法。为实现这一既定目标，提出了以下目标：(1)发展描述复杂多部件系统故障和更新过程分布的技术，重点研究系统的暂态现象和老化过程；(2)利用考虑维护成本的更新和半再生过程建立基于暂态公式的分析模型；(3)以维护成本最小为目标，利用最优化技术和启发式方法探索所得到的超越函数的凸性；(4)开发一套成本边界指标，以辅助分析成本选项的合理性和敏感性；(5)利用离散事件仿真对模型和算法的灵敏度和耐久性进行了验证。实际的工业数据将用于模型的测试和验证。今天的许多人造系统的特点是机械、电气和电子部件高度集成，以产生一个工作系统。随着高度集成度的提高，由于系统中个别组件或组件组发生故障而导致的故障易损性也随之增加。可靠且可行的预防性维护计划可确保机器的长时间运行和更高效的系统。提高生产率对于一家公司和一个国家的经济竞争力都是至关重要的。如果成功，作为本研究的一部分开发的工具将有助于实现有效的预防性维护计划。鉴于保持系统运行和防止灾难性故障的迫切需要，这一领域的研究对工业世界有很大的贡献。

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.