1. Tutorial DFD Cap 252 - I. Najwa AlGhamdi

2. context diagram  Why context diagram ?  To know Who will interact with system. What's the main input and output to/from system  What kind of stuff that should appear in context??  the main big process : the system  external entities : source and sink.  Data flow.  stuff that is not allowed to be there?  Date store

3. Q1  This system blocks sites with bad language.  The user will enter search words to the system, the system will submit those search words to a search engine.  after receiving the search results and keywords for each search result, the system will classify each search result as blocked or unblocked according to pre- specified criteria saved in a file in the system.  The system saves these search results in the search results database.  The system blocks the sites marked blocked.

4. Q1  1. This system blocks sites with bad language.  The system then returns the search results to the user.  If the user clicks on one of the URL’s in the search results the system will return a website to the user (if the site is unblocked) or will return a blocked site notification to the user (if the site is blocked).  The administrator (manager) can submit a request to delete all search results from the search results database, the system will delete them and notify the administrator (manager).  The administrator can send an update request to the system to update the criteria in the criteria file, the system will notify the administrator by an update-done notice.

5. Q1 – find out context diagram component  This system blocks sites with bad language.  The user will enter search words to the system, the system will submit those search words to a search engine. source : user Data flow : search word  after receiving the search results and keywords for each search result, the system will classify each search result as blocked or unblocked according to pre-specified criteria saved in a file in the system. Nothing  The system saves these search results in the search results database. Nothing  The system blocks the sites marked blocked. Nothing Show

6. Q1 – find out context diagram component  This system blocks sites with bad language.  The user will enter search words to the system, the system will submit those search words to a search engine. source : user Data flow : search word  after receiving the search results and keywords for each search result, the system will classify each search result as blocked or unblocked according to pre-specified criteria saved in a file in the system. Nothing  The system saves these search results in the search results database. Nothing  The system blocks the sites marked blocked. Nothing 0 Blocking system Search word

7. Q1  1. This system blocks sites with bad language.  The system then returns the search results to the user. Sink : user. Data flow : search results.  If the user clicks on one of the URL’s in the search results the system will return a website to the user (if the site is unblocked) or will return a blocked site notification to the user (if the site is blocked). source : user Dataflow : URL sink : user Dataflow : website,,block notification Show

8. Q1  1. This system blocks sites with bad language.  The system then returns the search results to the user. Sink : user. Data flow : search results.  If the user clicks on one of the URL’s in the search results the system will return a website to the user (if the site is unblocked) or will return a blocked site notification to the user (if the site is blocked). source : user Dataflow : URL sink : user Dataflow : website,block notification 0 Blocking system Search word Search result URL Website Block notification

9. Q1  1. This system blocks sites with bad language.  The administrator (manager) can submit a request to delete all search results from the search results database, the system will delete them and notify the administrator (manager). source : Manager dataflow : request to delete Sink : Manager dataflow : notification for deletion  The administrator can send an update request to the system to update the criteria in the criteria file, the system will notify the administrator by an update-done notice. source : Manager dataflow : request to update Sink : Manager dataflow : notification for updating Show

10. Q1  1. This system blocks sites with bad language.  The administrator (manager) can submit a request to delete all search results from the search results database, the system will delete them and notify the administrator (manager). source : admin - dataflow : request to delete Sink : admin -dataflow : notification for deletion  The administrator can send an update request to the system to update the criteria in the criteria file, the system will notify the administrator by an update-done notice. source : Manager dataflow : request to update Sink : Manager dataflow : notification for updating 0 Blocking system Search word Search result URL Website Request to delete Request to update Delete-notification uodate-notification

11. Q1

12. Q2  The user submit her/his name to the system  the system will tell the user if he is a boy or a girl or don’t know by looking up his name in database of names saved in the system.  If the system answer was don’t know, the system will ask the user if he is a boy or a girl the user will respond by typing the correct answer  the system will save the name and the gender(boy or girl) to the database of names.  The user also can send a question asking about names that starts with a specific letter, the system will send the names with the specific letter to the user.

13. Q2  The user submit her/his name to the system  the system will tell the user if he is a boy or a girl or don’t know by looking up his name in database of names saved in the system.  If the system answer was don’t know, the system will ask the user if he is a boy or a girl the user will respond by typing the correct answer  the system will save the name and the gender(boy or girl) to the database of names.  The user also can send a question asking about names that starts with a specific letter, the system will send the names with the specific letter to the user.

14. Q2

15. Q3  The management of the Underground train service have requested an automatic ticket machine to function as outlined.  The user of the machine asks for a destination ticket type (e.g. single, return or day return) and the machine displays the price.  When enough money has been put in, the machine issues a date- stamped ticket containing the issuing station, the destination, ticket type and price. If appropriate, the machine also gives change.  The machine records the number of tickets issued for each destination and the number of tickets of each type for each day. Once a week these statistics are transferred to the main computer.

16. Q3

17. Q4  To apply for a necessary vacation, an employee fills out a vacation application form stating the reasons behind the vacation and the number of days.  He\she then submits this application to their departmental secretary. A copy of this application is filed in the employee record.  The secretary then checks the employee record and the departmental schedules to see if this employee is eligible for a vacation. For an employee to be eligible, he\she need not have taken more than 20 days in sick leaves and necessary vacations since the beginning of the year.

18. Q4  If the employee has taken more than 20 days, the secretary rejects the application, updates the employee record and notifies the employee. If the employee has not taken more the 20 days, the secretary checks the departmental schedule. If during the requested vacation time there will be at least 7 employees working, then the secretary grants the vacation request, updates the employee record, and notifies the employee. If there would be less than 7 employees working during the vacation time, then the secretary checks the number of rejected vacation requests.

19. Q4  If it is 3 or less, the secretary rejects the application, updates the employee record, then notifies him\her of the result. If it is more than 3, then the secretary passes the application to the departmental manager to get his\her approval\disapproval. The manager checks the reasons behind the vacation, if he\she thinks it is necessary for the employee to leave then the manager sends his approval along with the application back to the secretary. Otherwise, the manager sends his\her disapproval along with the application back to the secretary. The secretary then updates the employee record and notifies him\her of the result.

20. Q4

21. Q5  The Customer comes to the store and picks movies. Once he\she is done, they go to the register to pay for their rentals. If they are new customers, the clerk asks them to fill a new customer form stating their name, address, and phone number. The clerk then enters this information into a computer terminal and a new customer record is created. If they are returning customers, the clerk asks for the ID. The ID is then entered into the system to get the customer record. The clerk then checks the customer record for overdue rentals. If the customer has not returned rented movies, the clerk informs the customer that he\she needs to return old movies before allowing them to rent new ones. If the customer has returned the movies late, then the clerk calculates the late fees. If the customer has been with the company more than 2 years, the customer is charged $1 per day per movie. If the customer has been with the company less than 2 years, the clerk checks the number of times the customer has been late returning movies.

22. Q5  If the customer has been late more than 10 times, he\she is charged $5 per day per movie. If the customer has been late between 7 and 10 times, he\she is charged $4 per day per movie. If the customer has been late between 4 and 7 times, he\she is charged $3 per day per movie. If the customer has been late less than 4 times, he\she is charged $2 per day per movie. The clerk then gives the customer a bill for the late fees. Then the clerk enters the new movies into the system as rentals into the customer record along with the due date and issues a bill with the new rental and gives the customer the movies. When a movie is returned, if it is returned on time, the clerk removes the rental from the customer record. If is late, the clerk adds a late notice in the customer record

23. Q5