What is the relation between creating business partner for Org unit and defining organizational model in Solution Manager ITSM?

Hi All

I have few questions regarding Support Team Determination.

Before making a support team, there is a step to exectue below capture screen.

After that, to define support, we define organizational Model.

My question is what is the relations between creating business partenr for Org unit and define organizational model?

I don't know exactly why run report 'HRALXSYNC'?

Please reply me.