Information System Analysis Lab 4

1. Information System Analysis Lab 4

2. Objectives • In this lab we will learn : ــComponents of DFD. ـــRules for Using DFD Symbols. ـــhow to create DFD using Visio. ـــ Examples.

3. Data Flow Diagrams (DFDs) • Data flow diagram (DFD) is a picture of the movement of data between external entities and the processes and data stores within a system.

4. Components of DFDs • Process • External Entity. • Data flows . • Data store .

5. Student details Student ID

6. Processes and data flows Incorrect

7. Data store

8. Data store Incorrect

9. External entities Incorrect

10. Things that you must avoid when drawing DFD diagrams

11. List the errors of this DFD

12. Example 1:Online Car Renter System Inputs: 1-Customer can enter rental requirements. 2-Customer can select a car. 3-Customer can reserve a car. Outputs 1-system should provide available cars. 2- system should provide total rental price. 3- System should provide invoice if customer reserves a car . Processes 1- system should be able to check car availability as per the customer requirements. 2- system should be able to calculate total rental charge for the customer’s rental requirements 3- system should be able to process credit card payment through the company bank 4- system should reserve the car for the customer by sending a notification to the garage.

13. Creating DFD 1-Draw Context Diagram Reservation Info Car Choice Rental Requirements 0 Online Car Rental System Notification Credit Card Info Available Car List Customer Bank Authorization Rental Summery Invoice Credit Card Notification Rental Notification Garage

14. Context Diagram • The system as single process. • Shows all the external entities that receive information from or contribute information to the system. • No data stores.

16. Example 2: Easy Travel Agency specifications EasyTravel is a travel agency specializing in family holidays. It holds lists of hotels and charter flights and creates organized holidays for clients. Currently the company uses a paper based system. The company its tasks by the following text: • Bookings are made either through a list of agents, or by direct approach from clients. • When a client/agent makes an approach, the Reservations Clerk selects appropriate flight and hotel details for the customer and makes a provisional booking. The details are entered onto a provisional booking file.

17. Easy Travel Agency specifications • The customer must confirm this booking within three days, by sending a deposit of 10% of costs. On receipt of this deposit, Reservations close the provisional booking and add the details to their full booking file. • Four weeks before the flight is due, Accounts send an invoice to the clients for the balance. Accounts notify Customer Services when the balance is received and Customer Services then send tickets and joining instructions. • Reminders are sent to customers three weeks and one week before departure. Although the company insists that payment is made at least one week before departure, it has been known that payment has been made and tickets received on the morning of the flight. • At the end of each month, commission of 15% is paid to any agents responsible for holidays commencing during that month.

18. Draw • context Diagram using Visio • For Easy Travel Agency system

19. any Q