DIFFERENCE BETWEEN PART COUNT, FAMILY COUNT AND ELECTRONIC COMPONENT TABS

Hello, 

I am currently using the FIDES ExperTool Software for the first time and despite having thoroughly read the ExperTool Guide, i struggle to understand the use of the Family Count and Part Count tabs.

From the tests i've run, they seem to be "optional" tabs : I can either input all the components in the Electronic Compenent, RF and HF Compenent tabs etc. OR input them in the Part Count tab OR in the Family Count tab. I have therefore assumed that the Part Count and Family Count tabs offer another way to input components into the ExperTool software but the reliability results aren't the same if you put a resistor in the Part Count Tab or in the Electronic Component tab.

Could Someone explain which method i should use and why?

Thank you to anybody who takes the time to answer my question.

Martin