Failure Mode and Effects Analysis

Abstract

Failure Mode and Effects Analysis, popularly known as FMEA, is a technique that compels designers to think on the possible failures of equipment and their consequences for achieving total reliability. All engineers without exception do apply FMEA in the design of electronic equipment to prevent obvious design errors, and examples are provided for the application. However, the detection of latent design errors requires applying FMEA systematically. The terms, the benefits, and the application of FMEA are explained with examples from electronic designs for the benefit of circuit designers. FMEA improves the competence of designers and enhances the reliability and maintainability (R&M) of equipment. The documentation of FMEA becomes an asset to organizations.

Appendices

Assessment Exercises

• 1. Say True or False:

  • (i) Proto-models of modules should be available for identifying the possible failure modes of the modules using FMEA.

  • (ii) FMEA is a knowledge based activity to identify the possible failure modes of modules.

  • (iii) Local, next higher level, and end effects of a failure mode could be identified for all electronic items.

  • (iv) Failure cause is identified for the failure mode of an item and not for the failure effect.

  • (v) The design actions to eliminate the failure causes identified in FMEA are corrective actions.

  • (vi) After performing FMEA on items, initiating preventive actions is based on the severity of local effect or next higher level effect or end effect.

  • (vii) Eliminating the failure causes identified in FMEA on modules is always accomplished by changing the circuit design of the modules.

  • (viii) The failure modes of a module are identified assuming the modules supplying input signals and DC voltages are functioning satisfactorily.

• 2. Define and explain the terms of FMEA:

  • (i) Failure mode

  • (ii) Failure effect

  • (iii) Failure cause

  • (iv) Preventive action

• 3. When performing FMEA on items, explain why the failure modes that are identified for the items should be unambiguous and independent.

Research Assignments

• 1. Perform FMEA on the products listed below, after identifying the indenture levels of the products. Identify at least one functionally critical component for the products and perform FMEA at component level also.

  • (i) SMPS

  • (ii) RF power amplifier

  • (iii) LED Lighting unit

  • (iv) Audio power amplifier

  • (v) Battery charger