15 walk throughs a week for APS principals

If I understood correctly, Winston Brooks has ordered principals
to do 15 walk throughs of their schools each week.

On the face of it, it seems like a great idea; no more principals
too busy in their offices to know what is going on in their schools.

Unclear at this point, where do principals find the extra hours in a day, to do the walk throughs?

A high school principal could easily spend an hour walking through a school. Even an elementary school principal might well spend an hour on such a venture.

Where do the extra hours come from; who will do the work that the principals are doing in their offices that keeps them from walking through their schools in the first place?