Exercices & Corrections Week 3

Exercise (2) Abstract from the example scenarios (p10&19) and put the Regnell’s approach in the Reference Framework

Regnell’s UCM (Use Case Model) 1. Withdraw Cash, normal case Actor: ‘ATM customer’ 1.IC Invocation Conditions: 1.IC.1 The system is ready for transactions. 1.FC Flow Conditions: 1.FC.1 The user’s card is valid. 1.FC.2 The user enters a valid code. 1.FC.3 The user enters a valid amount. 1.FC.4 The machine has the required amount of cash. 1.FE Flow of Events: 1.FE.1 The user inserts the card. 1.FE.2 The system checks if the card is valid. 1.FE.3 A prompt for the code is given 1.FE.4 The user enters the code. 1.FE.5 the system checks if the code is valid 1.FE.6 A prompt ‘enter amount or select balance’ is given. 1.FE.7 The user enters the amount. 1.FE.8 The system checks if the amount is valid 1.FE.9 The system collects the cash. 1.FE.10 The cash us ejected. 1.FE.11 A prompt ‘take cash’ is given. 1.FE.12 The user takes the cash. 1.FE.13 The card is ejected. 1.FE.14 A prompt ‘ take card’ is given. 1.FE.15 The user takes the card; 1.FE.16 The system collects receipt information. 1.FE.17 The receipt is printed. 1.FE.18 A prompt ‘take receipt’ is given. 1.FE.19 The user takes the receipt. 1.TC Termination condition: 1.TC.1 The system is ready for transactions. UCM is built during the analysis phase of UORE

Regnell’s SUM (Synthetized Usage Model) code fail ready The SUM is constructed during the synthesis phase aborted insert card re-enter code abort code invalid account number code card validation retry validation card invalid card ok code ok too many errors aborted The synthetized usage view for the ‘ATM Customer’ integrates different use case descriptions abort enter code disclaim card code code validation ready aborted code ok enter amount or select balance User action amount amount invalid ... amount validation abort System action amount ok ... take card message ready

Exercise (2) Regnell’s UORE (Usage Oriented Requirements Engineering) Form.Desc.Medium: Graphics(SUM), Text (UCM) Form.Desc.Notation: Semi-formal Form.Present.Anim: False Form.Present.Interac: None Content.Abstraction: Type Content.Context : Syst. Interaction, Syst. Internal Coverage.Func.: S, F, B Coverage.Intent.: Goal Coverage .Non Func.: False Content.Argumentation: False Purpose: Descriptive Life cycle. Duration: Persistent Life cycle.Op.: Capture, Integration

Exercise (3) You have been hired to create the requirements document for a new ATM. Decide whether each item in the following list is a stakeholder, a primary actor, a secondary actor, the SuD, or not an actor at all: The ATM The customer The ATM card The bank The front panel The bank owner The serviceman The printer The bank clerk The main bank computer system The bank robber List the primary actors

Exercise (3) Decide whether each item in the following list is a stakeholder, a primary actor, a secondary actor, the SuD, or not an actor at all: The ATM : the SuD The customer : a primary actor The ATM card : not an actor, a resource The bank : not an actor, The front panel : not an actor ; a component of the SuD The bank owner : a stakeholder (probably!) The serviceman : a primary actor The printer : not an actor; a component of the SuD The bank clerk : a primary actor (who refills the cash?) The main bank computer system : a secondary actor The bank robber : use your imagination!!!!! List the primary actors The customer, the serviceman, the bank clerk

List goals that the various ATM primary actors will have Exercise (4) List goals that the various ATM primary actors will have with respect to the ATM

Exercise (4) Serviceman Put ATM in working order Run ATM self test Bank clerk Restock money Refill supplies Customer Withdraw cash Deposit money Transfer money Check balance

Write the base scenario for the use case Withdraw Money Exercise (5) Write the base scenario for the use case Withdraw Money Using Fast Cash Option

Withdraw Money Using Fast Cash Option Exercise (5) Withdraw Money Using Fast Cash Option The customer runs card through the card reader; the ATM checks the validity of the card and if the card is valid, the ATM sends a prompt for PIN to the customer. The customer enters the PIN. If the PIN is valid, the ATM displays a table of possible amounts. The customer selects a withdrawal amount. If the system authorizes the amount, it delivers the card and the cash.

Exercise (6) 1- Brainstorm about possible conditions for failure in the use case Withdraw Money 2- List failure scenarios and Name them 3- Identify circumstances and outcome for each of them 4- Write the failure scenario comprising three wrong captures of the customer’s PIN

Exercise (6) Possible failure conditions - an expired card - not an ATM card - incorrect PIN - no credit 2- List failure scenarios - Withdraw Money with expired card - Withdraw Money with invalid card - Withdraw Money with incorrect PIN - Withdraw Money with no credit

Exercise (6) 3. Circumstances & outcome - Withdraw Money with expired card circumstances : the customer has an expired card outcome : card - Withdraw Money with incorrect PIN circumstances : the customer has a valid card but not the PIN outcome : “your card has been swallowed : please, contact your bank agency”

Withdraw Money with incorrect PIN Exercise (6) Withdraw Money with incorrect PIN The customer runs card through the card reader; the ATM checks the validity of the card and if the card is valid, the ATM sends a prompt for PIN to the customer. The customer enters the PIN. If the PIN is not valid, the ATM sends again a prompt for PIN to the customer. The customer enters the PIN. If the PIN is not valid, the ATM sends a third time a prompt for PIN to the customer. The customer enters the PIN. If the PIN is not valid, the ATM swallows the card and displays a message “your card has been swallowed, please contact your bank agency”

Exercise (7) 1- Brainstorm about possible variations of the course of actions in the base success scenario of the use case Withdraw Money 2- List variant scenarios and Name them 3- Identify circumstances and outcome for each of them 4- Write the variant scenario comprising two wrong captures of the customer’s PIN

Exercise (7) Possible variations of the normal course of actions - two captures of incorrect PIN - customer asks for a receipt 2- Name variant scenarios - Withdraw Money with a receipt - Withdraw Money with two captures of incorrect PIN 3- Outcome & circumstances Withdraw Money with a receipt circumstances : the customer has a valid card and credit on her account outcome : cash, receipt and card

Withdraw Money with two captures of incorrect PIN Exercise (7) Withdraw Money with two captures of incorrect PIN The customer runs card through the card reader; the ATM checks the validity of the card and if the card is valid, the ATM repeats at maximum twice and till the PIN is valid, a prompt for PIN is sent to the customer. the customer enters the PIN. If the PIN is valid, the ATM displays a table of possible amounts. The customer selects a withdrawal amount. If the system accepts the amount, it delivers the card and the cash.