Dear DR Salah,

Thank you for your valuable answer :)
But we already have KPI's in our company that states that every employee must be above the average of team (but they didn’t state how to calculate the productivity).

For example we calculate productivity as follows:-
We work in complaint department to solve customers' problems, so we solve customers' requests, so every employee take points on every solved request according to its difficulty and average handling time of this request and then we take requests points and divide it on working days of employee.
(Ex:- requests points / no# of working days = average of employee points)

Problems that we are currently facing are mainly stated in employee no# of working days as it differs from each employee to another that could affect team average.

I need your valuable advice if there is a book or a website that could give me different ways to calculate productivity.

Please if you need more clarification
Appreciate letting me call you if available.

Thanks in advance.