Rediscovered this article in Evernote during my daily notes-weeding practice. I’m sure I must have implemented it at one time, and did so again yesterday. It does make sorting my inbox much faster, though as usual, I find I overload myself with too many items to be done in one day.
It resembles Carl Pullein’s Time Sector System, which uses an algorithm of when will you do something, rather than prioritizing based on what you are doing.