if2036 scenario based-model

IF2036 Rekayasa Perangkat LunakSoftware Requirement

Sem II 2012/2013

Apa yang dimodelkan? Seperti apa modelnya? Bagaimana cara membuat modelnya?

Scenario-based Modeling

IF2036 RPL - Scenario-based Modeling

Apa yang dimodelkan? The ways in which end-users will interact with the

system Seperti apa modelnya?

Scenarios in the form of use cases, Activity diagrams, Swim lane diagrams

Bagaimana membuat modelnya?

Scenario-based Modeling


Apa itu use case? Apa itu actor? Apa itu skenario?

Use Case Diagram


Concepts in Use-Case Modeling

Actor

Use-Case

An An actoractor represents anything that interacts with the represents anything that interacts with the system. An actor is EXTERNAL!system. An actor is EXTERNAL!

A A use caseuse case is a sequence of actions a system is a sequence of actions a system performs that yields an observable result of value to a performs that yields an observable result of value to a particular actor.particular actor.

Use cases are the conduit between the end users Use cases are the conduit between the end users and the developers. One of their primary purposes is and the developers. One of their primary purposes is to serve as a communication vehicle, so that end to serve as a communication vehicle, so that end users and developers can clearly understand the users and developers can clearly understand the requirements.requirements.


Actor

Actor Actors are not part of the system,

they represent roles a user of the system can play.

An actor may actively interchange information with the system.

An actor may be a passive recipient of information.

An actor can represent a human, a machine or another system.

Actors are EXTERNAL


Actor Generalization Several actors can play the

same role in a particular use case

There are full-time and part-time students, both of whom can register for courses, and are seen as the same external entity by the use-case that does the registering.

The shared role is modeled as an actor, Student, inherited by the two original actors. This relationship is shown with actor-generalizations.

Student

Full-Time Student

Part-Time Student


A User May Have Different Roles

Charlie asstudent

Charlie as professor

Charlie

Professor

Student


Systemboundary?

ATM System

Bank Teller

Customer

Bank System

Actors and System Boundaries


Use-Case

Use-Case A use-case models a dialogue between

actors and the system. A use-case is initiated by an actor to invoke a certain functionality in the system.

A use case models a dialogue between one or more actors and the system that returns a result of measurable value to at least one actor.

A use-case is a complete and meaningful flow of events.

In order to "scope" the size of a use case, consider that a use case represents a major system usage goal for one or more of the actors that interact with the use case.

All use cases constitute all possible ways of using the system.


Packages in the Use-Case Model Packages are a general

grouping mechanism for grouping elements into semantically related groups.

You can use use-case packages to: Structure the use-case

model in a way that reflects the user types

Preserve secrecy in areas where it is needed

etc


Use-Case Flows of Events Has one normal, basic flow

(“Happy Path”) Several alternative flows

Regular variants Odd cases Exceptional flows handling error situations

“Happy Path”


What Are Scenarios ? A scenario is an instance of a use case


Use Case Diagram – ExampleRecycling Machine System

Returning Item

Generate Daily Report

Change Item

Customer Operator



Use-Case Diagram

homeowner

Access camera surveillance via the

Internet

Configure SafeHome system parameters

Set alarm

cameras

SafeHome


Use Case Diagram - Extension

Extends; defines alternative course of events: optional parts of use cases complex and alternative courses which

seldom occur separate sub-courses which are executed

only in certain cases situation where several different use

case can be inserted into a special use case


Use Case Diagram – Example - Extends

Returning Item

Generate Daily Report

Change Item

Customer Operator

Item Stuck

<<extends>>


Refinement of the Requirement Model

Print

Returning Item Generate Daily Report

<<uses>><<uses>>


Listing the activities performed by a single actor to accomplish a single function

Continue this process for each actor and each system function

Use-cases are written first in narrative form and then mapped to a template if more formality is required

Each primary scenarios should be reviewed and refined to see if alternative interactions are possible Can the actor take some other action at this point? Is it possible that the actor will encounter an error condition at

some point? If so, what? Is it possible that the actor will encounter some other behavior

at some point? If so, what?

Developing Use Cases


Latihan membuat diagram use case

Akan dibangun sebuah perangkat lunak untuk mendukung proses pendaftaran ulang mahasiswa secara online. Melalui aplikasi tersebut, mahasiswa dapat mengajukan usulan pengambilan matakuliah.

Selanjutnya, dosen wali dapat melihat usulan pengambilan matakuliah untuk disetujui/ditolak. Usulan yang ditolak dapat direvisi kembali oleh mahasiswa.

Usulan yang telah disetujui wali dapat langsung diproses oleh Petugas Administrasi untuk pencetakan KSM. KSM hanya bisa dicetak apabila status pembayaran SPP mahasiswa sudah beres. Informasi status pembayaran SPP diperoleh dari perangkat lunak lain yaitu SISKEU (Sistem Informasi Keuangan). Perangkat lunak ini juga akan berhubungan dengan perangkat lunak SIKAD (Sistem Informasi Akademik) untuk mendapatkan informasi tentang matakuliah yang ditawarkan pada semester tersebut, serta informasi transkrip nilai mahasiswa, agar dosen wali mendapatkan referensi untuk menyetujui/menolak usulan pengambilan matakuliah.


Actor ?





Mahasiswa Dosen Wali Petugas Administrasi SISKEU SIKAD

Actor


Use Case ?





Mengajukan Usulan Melihat Usulan Menyetujui Usulan Menolak Usulan Merevisi Usulan Memeriksa Status Pembayaran Melihat Daftar Kelas Melihat Transkrip Mencetak KSM

Use Case


Use Case Diagram


Mahasiswa memilih menu entri usulan Sistem menampilkan form entri FRS Mahasiswa mengisikan kode kuliah Sistem menampilkan informasi detil matakuliah

(nama, sks) Mahasiswa menekan tombol SIMPAN Sistem menyimpan data usulan ke dalam

basisdata

Skenario Mengajukan Usulan


Mahasiswa memilih menu daftar kelas Sistem menampilkan daftar kelas yang dibuka Mahasiswa memilih matakuliah dari daftar Mahasiswa menekan tombol SIMPAN Sistem menyimpan data usulan ke dalam

basisdata

Alternatif skenario


Mahasiswa memilih menu entri usulan Sistem menampilkan form entri FRS Mahasiswa mengisikan kode kuliah Sistem menampilkan pesan bahwa kelas untuk

kuliah tersebut tidak dibuka

Alternatif skenario (2)


if2036 scenario based-model

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