第二系统效应（英语：second-system effect），又称第二系统症候群（英语：second-system syndrome），由佛瑞德·布鲁克斯在《人月神话》中提出的经验概括。它认为，在完成一个小型、优雅而成功的系统之后，人们倾向于对下一个计划有过度的期待，可能因此建造出一个巨大、有各种特色的怪兽系统。第二系统效应可能造成软件专案计划过度设计，产生太多变数，过度复杂，无法达成期待，并因而失败。https://en.wikipedia.org/wiki/Second-system_effectThe second-system effect or second-system syndrome is the tendency of small, elegant, and successful systems to be succeeded by over-engineered, bloated systems, due to inflated expectations and overconfidence.[1]The phrase was first used by Fred Brooks in his book The Mythical Man-Month, first published in 1975. It described the jump from a set of simple operating systems on the IBM 700/7000 series to OS/360 on the 360 series, which happened in 1964.[2]