# Talk:Common mode failure

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## Unclear article

Please define the word event that is used in the first phrase.

The 3rd paragraph associates common mode failure with redundancy. The association is however too weak to put at this place. In addition, the association is not made sufficiently clear. The association seems to be that common mode failure is about statistically dependent events, whereas redundancy is about statistically independent events. In the following example of a RAID system, the differences are made clear; it explains why redundancy can fail due to common mode failures. To make a long story short, redundancy should be put in a seperate section, preferrably at the end of the article. The see also section should be extended correspondingly. Robert2s (talk) 12:44, 21 February 2010 (UTC)

## Merger proposal

There is really no new or additional information in this article that is not adequately covered in the Common-cause and special-cause page Bassplr19 (talk) 18:29, 22 September 2010 (UTC)

## Unmerge Proposal

I think there should be a separate page for common mode failure with a link to the Common-cause and special-cause page. The "common mode" disambiguation page says: "Common mode failure is when one event causes multiple systems to fail" and then directs to a page which doesn't say anything about that.

The use of "common mode/cause failure" in engineering is not adequately covered in the Common-cause and special-cause article. In engineering, it has a much narrower meaning. For example, a power supply or clock signal failure in an electronic circuit will cause multiple subsystems to fail. This is important when considering reliability or safety because a common input to redundant (duplicate) subsystems can cause them both to fail. If the probability a failure in one subsystem is p, then it would expected that an n channel system would have a probability of failure of pn. However, in practice, it is much higher (several orders of magnitude) because they are not statistically independent; there are always some mechanisms or functions that are shared. Thirteenangrymen (talk) 15:30, 7 April 2011 (UTC)