How To Make 0 level Diagram

For the designing of database we make 0 level diagram so because of this the any one can easily understand that how the database designed.
0 level have a combination of three parts.
1 . Entity
2 . Process
3 . Stored File

Here we have an example of 0 level Diagram

This is a 0 level diagram of a hospital management system.

Parts : -
 (1) Entities
- Patient
- Staff
- Food Service
- Payroll System
- Patient Account
 
  (2) Process
- Registration Process
- Patient Appointment
- Doctor Concern
- Patient Checkup
- Blood Group Verification
- Patient Tests
- Admit Patient
- Employee Pay Roll
- Treatment Bill

  (3) Stored File
- Patient Record
- Patient Report
- Employees Pay
- Patient Bills OR Account