Periodicity Posted on 13th December 201513th May 2021 by ThePD (The Project Definition) Periodicity is 1) a function whose output contains values that repeat periodically; 2) the tendency of an event to happen repeatedly. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in General and tagged word. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.