When to use hierarchy security?

[varshinims08]

Hello everyone, 

I am creating 5 different applicatiom in 5 different business units. All the application contains different teams, manager role and I want to restrict the data among the business units at the same time I want the user with the higher authority to have the access to all the data. Should I use Hierarchy security model or security roles are enough? If I use Hirerachy security model then which is better, manager or position hirerachy?

Thanks....