ANALISIS DAN PERANCANGAN SISTEM (APS) Pemodelan Perancangan

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ANALISIS DAN PERANCANGAN

SISTEM (APS)

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Tujuan perkuliahan

Memahami pendekatan terstruktur

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Agenda

Pemodelan terstruktur

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Metode

Functional Design

– Berorientasi pada fungsi

– Structured Design (Constantin & Yourdon, 1979),

Step wise Refinement (Wirth, 1971, 1976), Jackson

Structured Programming (Jackson, 1975), dll.

Object-oriented Design

– Berorientasi pada objek/data

– Booch (1994), Meyer (1988), Jacobson et all (1993),

dll.

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Pemodelan Terstruktur

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Functional Design Approaches

Transform Mapping

- langkah perancangan untuk tipe DFD

transform flow

:

– Incoming flow : aliran/jalur informasi eksternal masuk ke sistem untuk

ditransformasikan menjadi informasi internal

– Transform center : pusat transformasi di dalam sistem yang akan

mentriger informasi keluar dari sistem

– Outgoing flow : aliran/jalur informasi internal keluar dari sistem menjadi

informasi eksternal

Transaction Mapping

- langkah perancangan untuk tipe DFD

transaction flow

:

– Transaction : data tunggal yang mentriger satu atau beberapa aliran

data

– Transaction center : penghubung antara aliran-aliran data hasil

pentrigeran dengan data trigernya

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Functional Design Approaches

Transform flow

: tipe dasar DFD

Transaction flow

:

a b c d f g e h incoming flow transform center outgoing flow a c b d _e f g transaction transaction center action path

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Transform Mapping

Langkah-langkah Transform Mapping :

– Review dan refine DFD sampai ke level paling bawah

– Tentukan apakah DFD tsb. memiliki karakteristik tipe

transform flow

atau transaction flow

– Tentukan batas antara incoming flow, transform

center

dan outgoing flow

– Bangun first level factoring

– Bangun second level factoring

– Refine first iteration

Contoh Transform Mapping : SafeHome Security

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Transform Mapping –

Contoh

DFD level 1 :

1* Interact with user 2* Configure system 3 Activate /deactivate sytem 4 Display messages and status 5* Process password 6* Monitor sensors configuration information user commands and data Control panel Sensors Control panel display Alarm Telephone line configure request configuration data start stop password valid ID msg. A/D msg. configuration data configuration data sensor status sensor information alarm type telephone number tones

display information

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Transform Mapping –

Contoh

DFD level 2 : Monitor sensors

6.3* Format for display 6.2* Assess against setup 6.4 Generate alarm signal 6.1 Read sensors 6.5* Dial phone configuration information sensor information sensor status

sensor ID, type configuration data alarm type telephone number tones telephone number alarm data sensor ID, type, location

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Transform Mapping –

Contoh

DFD level 3 : Monitor sensors

1 Read sensors configuration information sensor status 2 Acquire response info 3 Establish alarm conditions 8 Generate pulses to line 4 Select phone number 5 Set up conn. to phone net 9 Generate display 6 Format display 7 Generate alarm signal

sensor ID, type

configuration data sensor information alarm type telephone number tones formated ID, type, location alarm data alarm cond. code, sensor ID, timing information list of numbers telephone number tone ready telephone number sensor ID, type,

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Transform Mapping –

Contoh

First level factoring : Monitor sensors

configuration information 8 9 6 7 1 2 3 4 5 Monitor sensors executive Sensor input controller Alarm conditions controller Alarm output controller

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Transform Mapping –

Contoh

Second level factoring : Monitor sensors

Monitor sensors executive Sensor input controller Alarm conditions controller Alarm output controller Format display Generate alarm signal Set up conn. to phone net Generate display Generate pulses to line Establish alarm conditions Select phone number Acquire response info Read sensors

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Transform Mapping –

Contoh

Refine first iteration : Monitor sensors

– Incoming controller dihapus : data input tunggal, cukup sederhana

– Transform controller dihapus dan digabung dalam satu modul : ada

penurunan tingkat kohesifitas

– Format display dan generate display digabung : sederhana

Monitor sensors executive

Establish alarm

conditions Alarm output controller

Produce display Generate alarm signal Set up conn. to phone net Generate pulses to line Acquire response info Read sensors

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Transaction Mapping

Langkah-langkah Transaction Mapping :

– Review dan refine DFD sampai ke level paling bawah

– Tentukan apakah DFD tsb. memiliki karakteristik tipe

transform flow

atau transaction flow

– Tentukan batas antara incoming path/transaction,

transaction center dan action path

– Bangun first level factoring

– Bangun second level factoring

– Refine first iteration

Contoh Transaction Mapping : SafeHome Security

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Transaction Mapping

Transaction structuring

r s a b d p q Transaction control b a d c1 q r s p Dispatcher Reception path

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Transaction Mapping

– Contoh

DFD level 2 : User interaction

3 Read password 2 Invoke command processing 4 Compare password w/ file 1 Read user command configuration information 5 Activate/d eactivate system 6 Display message & status 7 Read system data 8 Build configurat ion file command type start stop user commands and data configure request password raw configuration data configuration data A/D msg. configuration data configuration data

four digits display

information valid ID msg.

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Transaction Mapping

– Contoh

First/Second level factoring : User interaction

User interaction executive Read user command System configuration controller Invoke command processing Activate /deactivate system Password processing controller Read system data Build configuration file Read password Compare password w/ file Display messages & status

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Transaction Mapping

– Contoh

Arsitektur SafeHome Security Software

User interaction executive Read user command System configuration controller Invoke command processing Activate /deactivate system Password processing controller Read system data Build configuration file Read password Compare password w/ file Display messages & status SafeHome Security Monitor sensors executive Establish alarm conditions Alarm output controller Produce display Generate alarm signal Set up conn. to phone net Generate pulses to line Acquire response info Read sensors

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Pemodelan Berorientasi Objek

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OOA, OOD, OOP

Object-oriented analysis, design and

programming are related but distinct

OOA is concerned with developing an object

model of the application domain

OOD is concerned with developing an

object-oriented system model to implement requirements

OOP is concerned with realising an OOD using an

OO programming language such as Java or C++

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Konsep

Metode untuk melakukan dekomposisi arsitektur

sistem berdasarkan objek-objek yang dimanipulasi

oleh sistem yang sedang dibangun

Identifikasi dan mendefinisikan klas-klas tambahan

yg merefleksikan implementasi dari

kebutuhan-kebutuhan hasil analisis

Notasi = OOA

Proses :

– Perancangan sistem : struktur klas, user interface, data

management

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Struktur klas

Gunakan klas-klas hasil analisis dan tambahkan

sesuai dengan kebutuhan perancangan

Reuse

jika memungkinkan

packaging

: pengelompokan klas-klas yg sesuai

Vehicle color style year make VehicleOTS VIN validateVIN() Vehicle VIN color style year make validateVIN() VehicleOTS VIN validateVIN() Model dari OOA Model OTS

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Finding classes

Identifying object classes is often a difficult part of

object oriented design

There is no 'magic formula' for object

identification. It relies on the skill, experience and

domain knowledge of system designers.

Object identification is an iterative process. You

are unlikely to get it right first time.

Use domain analysis as before

Use a grammatical approach based on a natural

language description of the system

Base the identification on tangible things in the

application domain

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Finding classes

Derive them from the use cases

(descriptions/scenarios)

Look for data which must be stored or analysed

Are there external systems?

Are there any devices under the control of the

system?

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Object Design

Attributes

– Describe the state and characteristics of the object

– Must be typed : primitive or class

– Only name and type are mandatory

Operations

– Operations manipulate attributes and perform other

tasks

– Scope is the class

– Operation signature is composed of name,

parameters and return type

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Object Design

Sifat akses atribut dan operasi/service :

– private

(klas/objek ybs.)

– protected

(klas/objek ybs. dan turunannya)

– public

(semua klas/objek)

Algoritma operasi  untuk implementasi

spesifikasi dari setiap operasi

– operasi manipulasi data (set, delete, get, dll.)

– operasi komputasi

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Operations – polymorphism

Polymorphism means many (poly) shapes

(morph)

There are two kinds of polymorphism:

– Overloading

Two or more methods with different signatures with the

same name

They essentially do the same thing, e.g. class constructors

– Overriding

Replacing an inherited method class with another having

the same signature (no matter with different parameter’s

name)

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Latihan

A weather station is a package of software controlled instruments

which collects data, performs some data processing and transmits

this data for further processing. The instruments include air and

ground thermometers, an anemometer, a wind vane, a barometer

and a rain gauge. Data is collected periodically.

When a command is issued to transmit the weather data, the

weather station processes and summarises the collected data. The

summarised data is transmitted to the mapping computer when a

request is received.

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