1. Data Flow Diagrams

2. A diagram which shows the movement of data in a system.

3. Symbols Data Store Process A ‘database’ which stores any information / data. This can be physical or logical (on the computer. Anything that is happening either physical / logical. This is normally someone doing something. Any person that interacts with the system logical or physical. D1 1 Short desc External Entity

4. Notation (Cont) Data Flow. Symbols

5. When a customer searches (online) for all the films that are available to watch tonight at the cinema. The system looks at the films database and returns all the films and times. What is the external entity? What processes are there? Is there are a data store? What data flow is there? How to build a DFD from a scenario

6. When a customer searches (online) for all the films that are available to watch tonight at the cinema. The system looks at the films database and returns all the films and times. How to build a DFD from a scenario Process 1 Data Store D1 Symbols are done, but what is the problem? External Entity

7. How to build a DFD from a scenario Customer 1 Films D1 Date and Time Available Films Look up films Customer enters time and date to get all films

8. How to build a DFD from a scenario The customer selects (or books) a film (inc time) from the available films. The system updates the bookings database. The system confirms the booking.

9. How to build a DFD from a scenario The customer pays for the booking. He enters his credit card information. The payment table is then updated. The system returns a confirmation of the payment.

10. Task Create dfd’s from the scenarios given.