Assignment 1 Sample Solution PDF

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Summary

Nicolangelo Piccirilli...

Description

Assignment)#1)

Due!date:!January!21st,!2019!at!23.55! Submission:!through!Moodle! Please!Note:!This!is!an!individual!assignment!and!no!late!assignments!will!be!accepted.!) ! Question!#1:! Given!is!the!following!simplified!description!of!an!automated!teller!machine!(ATM)!with!the!following! money!withdraw!use!case.! A! customer! uses! this! ATM! to! withdraw! cash! from! their! savings! or! checking! account.! The! user! is! required!to!insert!a!bank!card!in!the!card!reader!of!the!ATM!and!to!provide!a!PIN!number!to!gain! access!their!bank!account.!PIN!and!card!numbers!are!validated!through!an!external!bank!server.!Once! the! card! is! validated,! the! customer! can! select! from! the! touchscreen! menu! one! of! two! possible! accounts!(checking/savings)!from!which!the!money!can!be!withdrawn.! Next,!the!customer!enters!the!amount!to!be!withdrawn!on!the!ATM!keyboard,!and!the!ATM!will!verify! that!the!current!account!balance!is!sufficient!by!connecting!to!the!external!bank!server.!If!the!account! funds!are!sufficient,!a!transaction!will!be!created,!the!money!being!dispensed!to!the!user!through!the! money!dispenser,!the!bank!account!will!be!updated!and!a!receipt!for!the!transaction!will!be!printed! using!the!ATM’s!printer.!

Given!this!information:! a.)!!CreateadomainmodelfortheATM! b.)!!CreateausecasediagramfortheATM! c.)!!Create!a!fully!dressed!scenario!for!the!withdraw!use!case!(2nd!paragraph!of!the! description)! d.)!!Create!a!system!sequence!diagram!for!the!withdraw!use!case!described!above! e.)!!Createasequencediagramforthewithdrawusecase–indicateanyGRASPpatterns! ! Question!#2! What!are!GRASP!patterns!and!how!are!they!related!to!sequence!diagrams?!Justify!the!different! GRASP!patterns!you!used!in!question!#1! Some!Open!source!tools!for!drawing!the!UML!diagrams!–others!available!on! http://en.wikipedia.org/wiki/ArgoUML!WhiteStarUML! http://www.fujaba.de/resources/installation.html! You!can!also!hand!draw!it!and!then!scan!it!with!your!smartphone!,!but!using!one!of!the!above!tools! is!probably!easier.!

1.a!

!! 1.b!

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1.c Number Name

1 Withdraw Money

Summary Priority

User withdraws money from his or her savings or checking account 5

Preconditions Postconditions Primary Actor Secondary Actor

Customer card and data has been verified by the System Customer has withdrawn money Customer ATM and Bank Server User has chosen to withdraw money Step Action 1 Customer chooses account type 2 ATM System asks for amount to withdraw 3 Customer enters amount System verifies account balance with Bank 4 Server 5 System creates transaction Transaction updates user's account through 6 Bank Server 7 ATM (money dispenser) dispenses money 8 Customer removes money 9 ATM (printer) prints receipt

Trigger Main Scenario

Extensions

10 11 Step

System shows closing message and dispenses customer's card User removes card Branching action

4a 4b 4c

System notifies costumer that the funds are insufficient System gives account balance System exits

9a 9b

System notifies customer that there is not paper available for printing the receipt System shows new balance

9c 9d

System shows closing message and dispenses customer’s card User removes card

1.d

Receipt

1.e High Cohesion

Controller Pattern

information expert

Creator Pattern

information expert

high cohesion

Creator Receipt

2. General Responsibility Assignment Software Patterns (GRASP) are principles or guidelines for assigning responsibility to objects in object-oriented design. Sequence diagrams show interactions between object and the order of this interactions. The relationship between sequence diagrams and these patterns is that people decide on responsibility assignment when drawing interaction diagrams, so these diagrams should reflect the application of the patterns and are a first step between the design and development of software. For the sequence diagram of the withdraw money use case I used the creator pattern between the ATM System and the Transaction class because ATM System has the initializing data that will be pass to the transaction when it is created. I also applied the controller pattern using ATM System class for handling input system events and trying to maintain modularity and high cohesion by creating individual instances of different elements (printer, dispenser, etc.) that have different responsibilities....