Presentation Transcript

1. Use case Diagrams

2. Topics: Modelingthe context of a system Modelingthe requirements of a system
3. Introduction Use case diagrams are central to modeling the behaviour of a system, a subsystem, or a class. Important for visualizing, specifying, and documenting the behavior of an element.
4. Getting Started A box with small buttons Being a developer, on should conceptually understand the system With UML, apply use case diagrams to visualize the behavior of a system, subsystem, or class
5. Getting Started A box with small buttons – Cellular Phone Place Conference Phone Call Place Phone Call <<extend>> Cellular Network Receive Additional Call Receive Phone Call <<extend>> Use Scheduler User Cellular Telephone
6. Terms and Concepts What is use case diagram ? ? ? ? A name and graphical contents that are a projection into a model. Its content distinguishes from other kind of diagrams Use Case Diagrams Use Cases Actors = +
7. Terms and Concepts What does Use case diagram contain ? ? ? ? Use cases Actors Dependency, generalization, and association relationships Packages and instances of use cases
8. Terms and Concepts Common uses To model the context of a system drawing a line around the whole system and asserting which actors lie outside the system and interact with it To model the requirements of a system what that system should do specify the desired behavior of the system
9. Modeling the Context of a System Things will live inside the system, some things will live outside it. credit card validation system accounts, transactions, and fraud detection agents credit card customers and retail institutions
10. Modeling the Context of a System Identify the actors that surround the system Organize actors – generalization/specialization provide a stereotype to actor if needed Provide communication path for actors and use case
11. Example – Credit Card Validation Credit Card Validation System Perform card transaction Process customer bill Retail Institution Customer Reconcile transaction Individual Customer Corporate Customer Manage customer account Sponsoring financial institute
12. Modeling the Requirementsof a System Establish the context of the system by identifying the actors that surround it. For each actor, consider the behaviorthat each expects or requires the system to provide. Name these common behaviors as use cases. Factor common behavior into new use cases that are used by others; factor variant behavior into new use cases that extend more main line flows. Model these use cases, actors, and their relationships in a use case diagram. Adorn these use cases with notes or constraints that assert nonfunctional requirements; you may have to attach some of these to the whole system.
13. Example Perform card transaction Report on account status Process Customer Bill Customer Detect card frauds Reconcile transactions Retail Institution Manage network outage Manage customer account Sponsoring financial institution
14. Problem - Restaurant Take Order Place Order <<actor>> Waiter <<include>> Place Phone Call Prepare order Customer <<extend>> Stock Low Restock Server Order Deliver Order Delivery Boy Cook Restaurant
15. Problem – ATM System Propose a use case diagram for an ATM machine for withdrawing cash. Make the use case simple yet informative; only include the major features. Identify use cases and actors and their relationship. Your diagram should include Customer operation over ATM machine. Role of administrator in registration of ATM to bank maintaining records.
16. Problem – ATM System ATM System Withdraw Transfer Funds Customer Deposit Money Register ATM at bank Bank Admin Read Log
17. End.