Dokokin Parkinson ra'ayi ne da ke cewa: "Aiki yana faɗaɗa don cike lokacin da ake samu don kammala shi." Wato, idan ka ba wa kanka wani ɗan lokaci don kammala wani aiki, aikin zai ɗauki tsawon lokacin, ko da kuwa da an kammala shi cikin ƙasan lokaci. Masanin tarihi kuma marubuci dan Burtaniya Cyril Northcote Parkinson ne ya fara bayyana dokar ta Parkinson a wata makala da aka buga a The Economist a cikin 1955.