I'm developing an internal tool (as an intern). We deal with a lot of hardware, which is all custom and managers have a hard time knowing who is developing on what machine. The three main things to track for this project will be Hardware, Projects and the Employees. I'm struggling with how to deal with the managers.

I was struggling with databases and of course I have to design one in my first internship. Any and all suggestions are greatly appreciated.

Here is my current ERD: