Common-mode failures in redundant VLSI systems: a survey

This paper presents a survey of CMF (common-mode failures) in redundant systems with emphasis on VLSI (very large scale integration) systems. The paper discusses CMF in redundant systems, their possible causes, and techniques to analyze reliability of redundant systems in the presence of CMF. Current practice and results on the use of design diversity techniques for CMF are reviewed. By revisiting the CMF problem in the context of VLSI systems, this paper augments earlier surveys on CMF in nuclear and power-supply systems. The need for quantifiable metrics and effective models for CMF in VLSI systems is re-emphasized. These metrics and models are extremely useful in designing reliable systems. For example, using these metrics and models, system designers and synthesis tools can incorporate diversity in redundant systems to maximize protection against CMF.