Bouncing Failure Analysis (BFA): The Unified FTA-FMEA Methodology

Bouncing Failure Analysis (BFA): The Unified FTA-FMEA Methodology (2005)
Zigmund Bluvband, Ph.D., ALD Ltd, Israel
Rafi Polak, M.Sc., ALD Ltd, Israel
Pavel Grabov, Ph.D., ALD Ltd, Israel

This paper introduces Bouncing Failure Analysis (BFA) – an innovative combination of two traditional and widely used Failure Analysis (FA) techniques: Failure Mode Effect Analysis (FMEA) and Fault Tree Analysis (FTA), presenting the methodology and the procedure able to maximize the advantages and at the same time to minimize the shortcomings of both known methodologies.
FMEA and FTA have three main differences: boundaries of the analysis, direction of analysis, and presentation of the analysis process and results. FMEA deals with single point failures, is built bottom-up, and is presented as a rule in the form of tables. FTA analyzes combinations of failures, is built top-down, and is visually presented as a logic diagram. By taking into account combinations of failures, FTA avoids the obvious shortcomings of FMEA. However, being heavily dependent on personal experience and knowledge, even “fine art” of a performer-analyst, FTA has a tendency to miss some of failure modes (FM) or FM combinations.
Most failure analyses and studies are based on either FMEA or FTA. Rarely, both FMEA and FTA will be performed, and when both are performed, these will be separate activities executed one after another – without significant intertwining.