一般工程系統的設計問題，都可視為供給(Supply)與需求(Demand)的問題。系統或組件是否能滿足設計需求，取決於設計的強度(供給條件)是否承受所遭受的最大作用力(需求條件)。然而，通常有許多影響設計或使用條件的因素是無法確定的。因此有必要考慮設計機率的特性，系統工程可靠度設計便而發展。 大部分的機械系統，在使用的時間或操作過程中，都會受到腐蝕、疲勞、潛變等因素，而造成系統組件慢慢退化。當應力大於強度的機率變大，失效率變會增大，可靠度退化的速度就會變快。因此，系統組件強度和可靠度退化快慢有密切的關係存在。利用本實驗室所建立的動態可靠度模式，進一步來分析預防保養對動態可靠度的影響。 系統組件在使用期間的性能退化可藉由不同的動作來改善。其中對系統進行預防維護作業是最有效的方法。在維護期間，往往必須考慮到系統效益，使系統在最小的成本中發揮最大的效益。因此設計並制定一套良好的維護策略，不僅可以有效降低失效率而避免失效的發生，並且可提高系統的效益。 General engineering system design questions are all visible for Supply and Demand. To fill the design requirements of system or element is according to whether the strength of design enduring the maximum effort .However , usually has many influences designs or the exploitation conditions factor is unable to determine. Therefore the consideration design probability characteristics are allowed and the reliability engineering of system is developed. Most mechanical systems are corroded, fatigued, creep in using process and components strength degenerated slowly. The hazard rate increased and the reliability degenerated quickly when the stress is bigger than the strength. Therefore, the components strength and reliability degeneration has close relationship. The dynamic reliability model is established in lab. to analyze the influence of preventive maintenance to dynamic reliability model. In order to reduce unexpected failure occurrence and extend running life of a system, taking preventive maintenance (PM) has been extensively used in many fields. During maintenance, taking care of system profit, making the most benefit of system in minimal cost. Therefore design and formulates a good maintenance strategies and avoid expiration and may enhance the benefit of system.
