In telecommunications, according to the Federal Standard 1037C of the United States, the term fault has the following meanings: An accidental condition that causes a functional unit to fail to perform its required function.
在电信領域，依照美国联邦标准1037C，故障有以下的意思： 意外情形使得功能單元（英语：functional unit）無法執行其應有的機能（隨機性故障）。