Masters Theses

Liang Xie

Keywords and Phrases

Cause-effect Chain Structure; Interval Probability

Abstract

"The traditional failure modes and effects analysis (FMEA) is a conceptual design methodology for dealing with potential failures. FMEA uses the risk priority number (RPN), which is the product of three ranked factors to prioritize risks of different failure modes. The three factors are occurrence, severity, and detection. However, the RPN may not be able to provide consistent evaluation of risks for the following reasons: the RPN has a high degree of subjectivity, it is difficult to compare different RPNs, and possible failures may be overlooked in the traditional FMEA method. The objective of this research is to develop a new FMEA methodology that can overcome the aforementioned drawbacks. The expected cost is adopted to evaluate risks. This will not only reduce the subjectivity in RPNs, but also provide a consistent basis for risk analysis. In addition, the cause-effect chain structures are used in the new methodology. Such structures are constructed based upon failure scenarios, which can include all possible end effects (failures) given a root cause. Consequently, the results of the risk analysis will be more reliable and accurate. In the new methodology, the occurrence and severity ratings are replaced by expected costs. The detection rating is reflected in failure scenarios by the probabilities of either successful or unsuccessful detections of causes or effects. This treatment makes the new methodology more realistic. The new methodology also uses interval variables to accommodate uncertainties due to insufficient data. The new methodology is evaluated and applied to a hydrokinetic turbine system. This turbine is horizontal axis turbine, and it is under development at Missouri S&T"--Abstract, page iii.

Advisor(s)

Du, Xiaoping

Committee Member(s)

Hosder, Serhat
Midha, A. (Ashok)

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2013

Pagination

viii, 77 pages

Note about bibliography

Includes bibliographical references (pages 43-44).

Rights

© 2013 Liang Xie, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Failure mode and effects analysis -- Testing
Failure mode and effects analysis -- Mathematical models
Failure mode and effects analysis -- Design
Value analysis (Cost control) -- Mathematical models
Hydraulic turbines -- Design
System failures (Engineering)
Reliability (Engineering)

Thesis Number

T 10360

Electronic OCLC #

858610334

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