Draw a level 0 data flow diagram (DFD) for the accompanying dentist office system.

When new patients are seen for the first time, they complete a patient information form

that asks for their name, address, phone number, and brief medical history, which are

stored in the patient information file. When a patient calls to schedule a new appointment

or change an existing appointment, the receptionist checks the appointment file for an

available time. Once a good time is found for the patient, the appointment is scheduled.

If the patient is a new patient, an incomplete entry is made in the patient file; the full

information will be collected when the patient arrives for the appointment. Because

appointments are often made far in advance, the receptionist usually mails a reminder

postcard to each patient 2 weeks before the appointment.

You can use any tool to draw the diagram.