Withdrawal Transaction Use Case Primary Actor: Customer Pre-conditions: The customer must have a...

Withdrawal Transaction Use Case

Primary Actor: Customer

Pre-conditions: The customer must have a valid ATM

card and PIN.

Post-conditions: The customer receives the cash

amount that he wanted to withdraw, with a receipt, if indicated.

The customer’s account balance is updated in the system.

Normal flow of events:1. The customer inserts ATM card into the ATM machine and enters PIN.2. The system validates the ATM card and PIN .3. The customer selects the ‘Cash Withdrawal’ option from the Options Menu.…Alternate flow of events:1. The customer has entered invalid PIN; Thesystem prompts the customer toenter a valid PIN.2. If ATM card is not compatible-The system rejects the ATM card and displays an error message….

Review

12

Get luggage

ready

[on car]

[on train]

«local precondition»Have a license

Turn on the car

To motorway

tollgate

Exit to xxxxx

tollgate

Go home with the

car

Go to the station with a

friend

Buy the ticket

Obliterate the ticket

Catch the train

When the trainarrives to xxxxx

Get off the train

The trainderail

Car crash

The friend goes home

Go home with bus

Go to Heaven/Hell ;)

Go to Heaven/Hell ;)

Study for 5

minutes

[xxxxx is a long way]

[else]

Catch the

ticket

Fill up with fuel

[the tank is full]

[else]

Pay the ticket

Strategy Pattern

Decorator Pattern

UML Summary

• UML: a graphical language for modeling and designing software

• Semi-formal models using syntax and semantics

• UML 2.0 standard

• 3 stages of design before coding: business modeling (initiation), requirement analysis (what to do), architecture (how to do it)

• UML as a family of languages: extensibility - UML for real-time systems, e.g., meta-class, constraints

• Best open source UML tools: http://apps.open-libraries.com/best-OPEN-source-uml-tools/

UML Diagrams Summary

• Use Case Diagram: actor and use cases

– 2 usage: mainly for requirement (sometimes business modeling), a communication between users, customers, designers

– 4 elements: actor, system boundary, use cases, association

– 4 rules to write good use case diagram: less ambiguity, complete, consistent, no design details - cross check with text requirement

– 3 use case relations: include, extend, generalization/specialization

– 4 key elements in use cases: name, actor, pre/post conditions, flow (main, alternative flows), sometimes relations with other use cases

UML Diagrams Summary

• Sequence diagram: object interactions

– Requirement analysis – describe use cases, find more objects

– 4 elements: objects (actor), lifetime, activation, messages

UML Diagrams Summary

• Class Diagram: class and class relations

– Requirement and architecture design

– 3 elements: name, attribute (optional), operation (optional)

– 2 types of class relations: association (aggregation/composition), generalization/specialization – inheritance

– Identify names in the requirement as classes

UML Diagrams Summary• Activity diagram: capture an activity/action -- unit of executable

functionality

– Business modeling, requirement - both data and control flow, concurrent modeling

– 2 types of elements

1. Activity nodes • Parameter nodes• Action nodes• Control nodes: decision/merge, join/fork, initial/final/flow final• Object nodes (pin): value pin, exceptional pin

2. Activity edges• Direct, Weight (optional) - the minimum number of tokens that must

traverse the edge at the same time• Control /object edges