Authors:

Once a week, do a thorough review of all your projects in as much detail as you need to. If you do, your systems will work. If you don't, no system will work.

David Allen (2011). “Ready For Anything: 52 productivity principles for work and life”, p.82, Hachette UK
Once a week, do a thorough review of all your projects in as much detail as you need to. If you do, your systems will work. If you don't, no system will work.