How to perform an internal mangement audit? (not the ISO more on performance of the managers and company)? -

I wanted to check the performance of each department managers. I already have the questionnaires but I don t know how to give weight in each question or at least how to do the statistics in each question

Basically the weight is depend on the company requirement, you can set it themself. What you need to do is listed down what is the most important factor as a manager or saying which point is more important that helps company, then give it more weight.