Productivity formula

Hey

I'm new here and need some help with a formula. After searching alot on the internet I found this question gets asked a lot but Im really having trouble with the maths and formula behind my excel.

I basically need to find a formula which will allow me to to find the productivity of our staff during there working hours which can vary.

I've attached a sample spread sheet and greyed out the columns which arent relevent to this formula at the moment but are there as place holders so any help with the formula you give me wont change.

So here is what I need help with if possible.

Our target for once peice of work being completed is one every 45 minutes. So if Mr A works 2 hours and completed two peices of work I need to find the productivity for this in a percentage in the last column. If Mrs B only worked 1 hour that day but managed to do 3 the her productivity should be over 100%

This spreadsheet is a work in progress and I may need some help in the future as well but I hope to become a contributing member of the forum.

Many thanks