Employee Productivity Percentage

Hi,

I am really struggling.

I have a form, where our employees fill the data in the screenshot below, date, name, task they are doing [product building], how many they built and how long in total they were doing it. I then have a formula to work out how long they spent on each product, they do this daily.

I have specified in another form, all the products, this includes a field for the expected time per product.

I am trying to get a calculation of productivity of each employee on our report. At the moment we have everything reported as expected, except percentage productivity.

I have tried creating a formula for expected time per product / actual time per product * 100 but it didnt work.

Any help and advice is appreciated, I am a complete novice at this.