Design Stage: Based on the Case study

Data Flow Diagrams

•Data flow diagram (DFD) is a modeling technique that illustrates and explains the movement or flow  of information in a process based on the inputs and outputs. 

The DFD below explains the movement of information in a mail  order computer system

DFD is very useful in explaining how data flows with any computer system being developed.

Some common symbols used  DFD

 

When developing a DFDs it is expected that conventional symbols are used.

DFD Activity

 Examine the following instruction outline and then is how DFD has been drawn to model the situation. 

Instruction

When a patient arrives at Mosspark Surgery with a repeat prescription request, the receptionist checks the prescription file and writes out a prescription. This has to be authorized by the doctor before being passed to the resident chemist for dispensing. The chemist then gives the prescription to the patient. If the patient is entitled to free prescriptions, the chemist verifies this and fills in the appropriate details on a form, which is filed in the free prescriptions file. Otherwise the chemist takes the appropriate amount of money from the patient and gives them a receipt.

Below is DFD that represents the above instructions

Based on your research on the Taxi system suitable for the Red Dragon Taxi Company, you will drawn or design a detailed Data Flow Diagram for the client.

Your Data flow diagram activity will be into in two sections;

a)     Detailed instructions outline providing all the details of how data will flow in the proposed Taxi management System

b)     A comprehensive DFD that models the situation described above.

N/B

-       Assessment criteria will be ready over the weekend

-       Work should be done independently

-       More research on DFD symbols and using them will be of advantage

-        Design stage work will be due Friday  2^nd May 2014