This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 1 ME4214 Design for Product Safety Modeling System Failures Part II: FMEA Dr. David Yuen Department of Mechanical Engineering The Hong Kong Polytechnic University 2 What is FMEA? • Failure modes, effects analysis (FMEA) is a methodology to identify and analyze: – All potential failure modes of the various parts of a system – The effects these failures may have on the system – How to avoid the failures, and/or mitigate the effects of the failures on the system • FMEA is a technique used to identify, prioritize, and eliminate potential failures from the system, design or process before they reach the customer – Omdahl (1988) • FMEA is a technique to “resolve potential problems in a system before they occur” – SEMATECH (1992) 3 FMEA and FMECA • Today, FMEA is often used as a synonym for FMECA (Failure modes, effects and criticality analysis). The C in FMECA indicates that the criticality (or severity) of the various failure effects are considered and ranked. • The distinction between the two terms has become blurred. 4 Background • FMEA was one of the first systematic techniques for failure analysis • FMEA was developed by the U.S. Military. The first guideline was Military Procedure MIL-P-1629 “Procedures for performing a failure mode, effects and criticality analysis” dated November 9, 1949 • FMEA is the most widely used reliability analysis technique in the initial stages of product/system development • FMEA is usually performed during the conceptual and initial design phases of the system in order to assure that all potential failure modes have been considered and the proper provisions have been made to eliminate these failures 5 What can FMEA be used for? • Assist in selecting design alternatives with high reliability and high safety potential during the early design phases • Ensure that all conceivable failure modes and their effects on operational success of the system have been considered • List potential failures and identify the severity of their effects • Develop early criteria for test planning and requirements for test equipment • Provide historical documentation for future reference to aid in analysis of field failures and consideration of design changes • Provide a basis for maintenance planning • Provide a basis for quantitative reliability and availability analyses. 6 FMEA basic questions • How can each part conceivably fail? • What mechanisms might produce these modes of failure? • What could the effects be if the failures did occur? • Is the failure in the safe or unsafe direction? • How is the failure detected ? • What inherent provisions are provided in the design to compensate for the failure?...
View Full Document
- Spring '10
- Mechanical Engineering, Failure mode and effects analysis, Concept FMEA FMEA Design Design FMEA FMEA, Potential Failure Mode