Productivity Model deals with the relationship between the resources used in production and the final output. It usually falls into one of three categories, these are models based on a specific company, models based on an entire industry, and models based on an entire national economy. It is a measurement method which is used in practice for measuring productivity. Productivity model is a more complicated and detailed version of a production function. It must be able to solve the formula Output / Input when there are many different outputs and inputs.