system modeling updated

8/8/2019 System Modeling Updated

http://slidepdf.com/reader/full/system-modeling-updated 1/20

Presentation on System Modeling

Team members:

Ganga Deep Karki(03)Jyoti Karki(08)

Hira G. Maharjan(19)



Topics Covered

System modeling & Use case modeling

Benefits of Use Case Modeling

Purpose of Use Case Modeling

System concepts for use case modeling

How to draw use case diagram

Uses of use case diagram

Summary

References



System Modeling &Use case Modeling

System modeling helps the analyst tounderstand the functionality of the system and

models that are used to communicate with

customers

Use case modeling it the process of modeling a

system¶s functions in terms of business events,

who initiated the events, and how the system

responds to those events.



Benefits of Use Case Modeling

Tools for capturing functional requirements

Assists in decomposing system scope

Provides means of communicating with usersand other stakeholders

Provides means of identifying, assigning,tracking, controlling and managing systemdevelopment activities

Tools for requirement traceability

Starting point for identification

Functional specification for design



Purposes of Use Case Modeling

To model a system, important aspect is to capture

dynamic behavior

Behavior of system when it is running/operating

Basic four purposes:

Gathering requirements

Get an outside view of system

Identify factors influencing the system

Interaction among requirements (actors)



System concepts for Use Case

ModelingTwo primary arti

factsA)Use case diagram

Depicts interaction among system, external

system and usersGraphically describes who use the system

and in what ways users expect to interact

with the system.Important process is the functional

decomposition



System Concepts (contd«.)

B) Use case narrative

Textual description of events, user interaction

with system to accomplish the task.

Use case

Tools that identifies and describes the systemfunctions

Represent graphically by ellipse Use Case Symbol

Name appears above, below or inside.

The characteristics of a use case are :

A use case is always initiated by an actor

A use case provides value to an actor

A use case is complete



System concepts(contd«.)

Actors

any person, organization, or system that

interacts with application but is external to it

Primarily four types of actors:

Primary business actor:

e.g. the employee receiving the paycheck

Primary system actor:

e.g. the bank teller entering deposit informationExternal server actor:

e.g. the credit bureau authorizing a credit card charge

External receiver actor:

e.g. the warehouse receiving a packing slip




Relationship

How elements are associated

Describes the functionality

(a) AssociationRelationship between actor and use case

(b) Extension use case

Extends the functionality of original use case

Arrowhead line beginning & pointing towardextending

<<extends>>




(c) Abstract use caseReuse

Reduce redundancies

Labeled as <<uses>>/<<includes>>

(d) Depends onRelation between use case

Indicating one cannot be performed until another has been performed.

Provide model tool for planning and scheduling<<depends on>>

(e) Inheritance

Mechanism of making new class from existing one



How to draw use case diagram

Identify following items:Functionalities

Actors

RelationshipFollow following guidelines to draw an efficient

use case diagram:Meaningful name to identify the functionalities

Suitable name for actor Show relationship and dependencies

Don¶t include all relation identify requirements

Note to clarify important points



Examples:

Restaurant Management System



Payroll System



ATM



Course Management System



Uses of Use Case Diagram

Requirement analysis and high level design

Model the context of a system

Forward and reverse engineering.



SUMMARY

System modeling helps the analyst tounderstand the needs of the stakeholders and

the reasons why the system should be

developed.

Use case modeling is the process of modeling

a system function in terms of business events,

who initiated the events and how the system

responds to those events. Some of the benefits of use case modeling



SUMMARY (contd..) Four purposes of use case modeling

System concepts for use case modeling is

based on two primary artifacts:1. Use case diagram

2. Use case narrative

We have also some overview on what is use

case, actors, relationships (extends, uses,

depends on, inheritance) and so on. How to draw use case diagram along with

suitable example.

At last, uses of use case diagram.



REFERE NCES Jeffrey L Whitten & Lonnie D Bentley, Systems Analysis and

Design Methods, 7th Edition

Lecture notes of Information System by Er. Sunil Poudel

Object Oriented System Course Manual by Er. Babu Ram

Dawadi

Internet Sites: http://en.wikipedia.org/wiki/

http://www.georgehernandez.com/h/xComputers/UML/Media/UseCaseD

iagram.gif

http://www.threesl.com/images/use-case-diagram-1.gif

http://www.featuredrivendevelopment .com/files/images/daryaUse_Case

_Diagram.jpg

http://www.unc.edu/~ jj/plone/Use%20Case%20Diagram.jpg

http://argouml-stats.tigris.org/documentation/manual-

0.24/images/tutorial/atm_use_case_diagram_multiplicity.gif

http://www.andrew.cmu.edu/course/90-754/umlucdfaq.html



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THANK YOU

FORATTENTION

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system modeling updated

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