Lifetime Posted on 5th December 20156th October 2020 by ThePD (The Project Definition) A Lifetime is a period of time during which a person is alive, or something lasts or exists. 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 health. 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.