System Reliability Analysis with Dependent Component Failures during Early Design Stage


It is desirable to predict product reliability accurately in the early design stage, but the lack of information usually leads to the use of independent component failure assumption. This assumption makes the system reliability prediction much easier, but may produce large errors since component failures are usually dependent after the components are put into use within a mechanical system. The bound of the system reliability can be estimated, but is usually wide. This wide reliability bound makes it difficult to make decisions, such as evaluating and selecting design concepts, during the early design stage. This work develops a new methodology that makes the system reliability prediction more accurate by considering the dependence between component failures. The following situation is addressed: The reliability of each component and the distribution of its load are known, but the dependence between component failures is unknown. With a physics-based approach, an optimization model is established so that a narrow bound of the system reliability can be generated. Two examples demonstrate that the proposed methodology produces a narrower system reliability bound than the traditional reliability bound, thereby better assisting decision making during the early design stage.

Meeting Name

ASME 2015 International Mechanical Engineering Congress and Exposition (2015: Nov. 13-19, Houston, TX)


Mechanical and Aerospace Engineering

Keywords and Phrases

Decision making; Design; Forecasting; Optimization; Product design; Reliability; Safety engineering; Component failures; Design concept; Early design stages; Independent components; Mechanical systems; Optimization modeling; Product reliability; System reliability; Reliability analysis

International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


File Type





© 2015 American Society of Mechanical Engineers (ASME), All rights reserved.

Publication Date

01 Nov 2015