just do it
It is not too late to start WW. However, I would suggest you read the Launching Unit/Nuts and Bolts to see the management part of it. To me that is one of the essential elements for WW success. You may already have something in place, but it was a definite eye opener for my colleagues and me because it went into minute detail on how to get the students working independently, from what supplies you need to how they are distributed, how to group students, how to conference, etc.