DOC PREVIEW
Toronto CSC 340 - Lecture 15 - Modelling System Interactions

This preview shows page 1-2-3-4-5-6 out of 17 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 17 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 17 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 17 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 17 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 17 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 17 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 17 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

University of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 1Lecture 15:Modelling System Interactions Interactions with the new system How will people interact with the system? When/Why will they interact with the system? Use Cases introduction to use cases identifying actors identifying cases Advanced features Sequence Diagrams Temporal ordering of events involved in a use caseUniversity of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 2Moving towards specification What functions will the new system provide? How will people interact with it? Describe functions from a user’s perspective UML Use Cases Used to show: the functions to be provided by the system which actors will use which functions Each Use Case is: a pattern of behavior that the new system is required to exhibit a sequence of related actions performed by an actor and the system via adialogue. An actor is: anything that needs to interact with the system: a person a role that different people may play another (external) system.University of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 3CampaignManagerAccountantChange aclient contactAdd a new clientRecord client paymentStaff contactUse Case Diagrams Capture the relationships between actors and UseCasesUniversity of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 4Staff contactActorChange client contactCommunicationassociationSystem boundaryUse caseNotation for Use Case DiagramsUniversity of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 5Add new staff memberAdd new staff gradeCalculate staff bonusesChange gradefor staff memberAccountantChange ratefor staff gradeExampleUniversity of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 6<<extends>>Check CampaignBudgetPrintCampaignSummary<<uses>>Find Campaign<<extends>> and <<uses>> <<extends>> when one use case adds behaviour to a base case used to model a part of a use case that the user may see as optional system behavior; also models a separate sub-case which is executed conditionally. <<uses>>: one use case invokes another (like a procedure call); used to avoid describing the same flow of events several times puts the common behavior in a use case of its own.University of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 7DriverMechanic<<extends>><<uses>>GasAttendant<<uses>><<uses>>Sample use cases for a car<<uses>>Fix CarCheck OilDriveFill UpFix car onthe roadTurn OnEngineUniversity of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 8ProvideconstraintsEditConstraintsWithdrawValidateUserSchedulemeeingInitiatorParticipant<<uses>><<extends>><<uses>>Meeting Scheduler ExampleGenerateSchedule<<uses>><<uses>><<uses>>University of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 9Generalizations Actor classes It’s sometimes useful to identify classesof actor E.g. where several actors belong to asingle class Some use cases are needed by all membersin the class Other use cases are only needed by somemembers of the class Actors inherit use cases from the class Use Case classes Sometimes useful to identify ageneralization of several use casesGeneralisation relations:Read as: “is a member of” or just “is a”University of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 10Identifying Actors Ask the following questions: Who will be a primary user of the system? (primary actor) Who will need support from the system to do her daily tasks? Who or what has an interest in the results that the system produces ? Who will maintain, administrate, keep the system working? (secondaryactor) Which hardware devices does the system need? With which other systems does the system need to interact with? Look for: the users who directly use the system also others who need services from the systemUniversity of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 11Finding Use Cases For each actor, ask the following questions: Which functions does the actor require from the system? What does the actor need to do ? Does the actor need to read, create, destroy, modify, or store some kindsof information in the system ? Does the actor have to be notified about events in the system? Does the actor need to notify the system about something? What do those events require in terms of system functionality? Could the actor’s daily work be simplified or made more efficient throughnew functions provided by the system?University of TorontoDepartment of Computer Science© 2004-5 Steve Easterbrook. This presentation is available free for non-commercial use with attribution under a creative commons license. 12Documenting Use Cases For each use case: prepare a “flow of events” document, written from an actor’s point of view. describe what the system must provide to the actor when the use case isexecuted. Typical contents How the use case starts and ends; Normal flow of events; Alternate flow of events; Exceptional flow of events; Documentation style: Choice of how to


View Full Document

Toronto CSC 340 - Lecture 15 - Modelling System Interactions

Documents in this Course
Scoping

Scoping

10 pages

Load more
Download Lecture 15 - Modelling System Interactions
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Lecture 15 - Modelling System Interactions and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Lecture 15 - Modelling System Interactions 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?