Transcript AUSI-13- (Software)

AUDIT SISTEM INFORMASI
Standard Software
Information Architecture
Disiplin Web Science
1. Bukan tentang
"WWW" SAJA
2. Tentang
informasi
terdistribusi dan
saling terkait
secara hyperlink
3. Interdisiplin
Trend yang ada
1. Web 0.0 (Era sebelum Web, radio, BBS dan
lain sebagainya)
2. Web 1.0 (Universal akses, Konten yang
portabel, dan hyperlink
3. Web
2.0
(Konten
yang
dihasilkan
user,Social network, (coercive), Mobile
access)
4. Web 3.0 (Fokus pada layanan universal ,
Berbasiskan
semantik,
Menunjang
interoperabilitas)
Membuat aplikasi Web? Gampang
1.
2.
3.
4.
5.
Berbasiskan web
Linux
Apache
MySQL
PHP
PHP
MySQL
Inovasi teknologi pendidikan
Keterbatasan jaringan
Presentasi secara "REMOTE
seperti streaming
ATBC 2010 - Bali oleh 150
peserta dari 20 negara
N
Portal pemerintah yg aman
Content Management System
yang dibangun dari scratch
untuk kebutuhan pengguna non
teknis
(wartawan,
pegawai
pemerintah)
Berita dapat dimasukkan dari
semua satuan kerja, tetapi
tetap
dengan
mekanisme
persetujuan
Ada fasilitas "preview" semua
situs (bukan hanya 1 halaman)
Mendukung tampilan mobile
Tersedia
untuk
badan
pemerintah melalui Univ. Putra
Indonesia “YPTK” Padang
Trend yang ada
1. Web 0.0 (Era sebelum Web, radio, BBS dan
lain sebagainya)
2. Web 1.0 (Universal akses, Konten yang
portabel, dan hyperlink
3. Web
2.0
(Konten
yang
dihasilkan
user,Social network, (coercive), Mobile
access)
4. Web 3.0 (Fokus pada layanan universal ,
Berbasiskan
semantik,
Menunjang
interoperabilitas)
Sistem Informasi Lanjut
• Manusia, organisasi
• SOP (Business Engineering)
• Cultur (index Hofstede)
• Pengguna (Ethnography, Activity Theory,
Groupware Task Analysis)
• Menu/GUI ^ Concurs Task Tree (CTT),
Predicate Action,
• Assurance ^ software verification,
Tingkat lanjut
Requirement Analysis
• Requirement Engineering (Misuse, LWBA, I*)
• Specification Method (Formal, Z, VDM, TLA,
Informal, Controlled Lang)
Design
Notation for Design (UML, SDL, IDEF), Workflow model
(BPMN, swimlane, SOP_INFO)
Paradigm of system (Language Oriented, Neural
Network, Fuzzy etc)
User Model (GOMS, Activity Theory etc)
(CTT, GTA, HTA etc), Menu
Fungsi notasi SOP
Penggunaan notasi ini berdasarkan beberapa
alasan utama yaitu:
Penjabaran dengan jelas siapa/organisasi mana yang
bertanggung jawab untuk melaksanakan suatu akfitas.
Penjabaran dengan jelas, alur dokumentasi yang ada.
Sehingga dapat dilihat persyaratan dokumen yang
dibutuhkan pada tiap aktifitas.
Penjabaran dengan jelas alur koordinasi dan interaksi
antar personal/orgranisasi yang terlibat.
Penjelasan rentang waktu dilaksanakannya suatu
Cara membuat SOP
1. Bagi menjadi tugas-tugas (task)
2. Identifikasi "Aktor" (orang/organisasi) yang
terlibat pada tugas tersebut
3. Identifikasi sub proses yang dilakukan oleh
tiap aktor untuk mengerjakan task tersebut
4. Identifikasi informasi yang mengalir (yang
dibutuhkan dan dihasilkan dari tiap sub
proses)
Integrated view of BBSDM
Spesifikasi Sistem
• Untuk berkomunikasi dengan berbagai
pihak dalam pengembangan,
pengembang, pengguna, manajer
proyek dsb.
•
Digunakan
dalam
pengembangan
(validasi,
disain, implementasi, testing)
proses
verifikasi,
• Sebagai bagian dari kontrak (aspek
legal)
Sumber kesalahan requirement
1. Kegagalan mengelola konflik secara efektif
2. Ketidak gamblangan pernyataan yang jelas tentang
masalah disain yang harus dipecahkan
3. Terlalu banyak disambiguasi yang tak dideteksi
4. Tak mengetahui siapa yang bertanggung jawab
untuk apa
5. Kurang peduli terhadap resiko requirement
Bahasa alami (Natural Language)
• Keuntungan:
• deklaratif
• luwes
• powerful
• diketahui, tak perlu belajar khusus
• berguna bagi pengguna biasa
Kerugian :
• tidak jelas
• tidak presisi
• ambiguous
• bergantung pada pengguna dan konteks
•
Bahasa formal
• Keuntungan:
• sintaks dan semantik yang telah didefinisikan
sebelumnya
• presisi
• unambiguous
• dapat diproses mesin
• Kerugian
• jarang dengan domain aplikasi
• memodelkan domain aplikasi
• notasi yang tidak biasa
• proses belajar khusus
Eksplisit vs Implisit
• Bahasa formal perlu menyatakan
segalanya secara eksplisit
• Memproses bahasa alami harus
mempertimbangkan elemen-elemen
implisit
• Elemen implisit dapat menyambung
kalimat membentuk teks yang koheren
Mengapa processable
English
•
Req.
Informal
:
UNTUK
BERKOMUNIKASI
dengan
pihak
dalam pengembangna sistem
• Req. Formal requirement : UNTUK
memverifikasi, validasi dan
pengembangan lebih baik
• Ada gap antara informal dan
formal.
Bhs. alami sebagai bhs.
formal
• Awalnya digunakan diindustri untuk dokumentasi
teknis
• Subsistem dan bahasa alami penuh dengan grammar
yang terbatas dan gaya tertentu yang
direkomendasikan
• Mereduksi ambiguitas dan meningkatkan
komprehensibilitas
• Bisa dicheck menggunakan komputer
• Penterjemahan mesin
• Menggabungkan keuntungan dari bhs. formal dan
informal.
Tahapan Development
1)
Global Disain
• Use Case
2)
Requirement Analysis ^ LWBA
• Features
• Organizational/Policy
3)
Process Analysis
• Information Flow
• Standard Operating Procedure ^ SOP_INFO
4)
Design dengan "PATTERN"
• Prototype dengan Wireframe tpool dan Report Tools
5)
Evaluasi Prototype ^ Early Usability
Introduction
•
Computer software is:
–
–
–
A group of programs that connects user with
computer devices
Comprised of a sequence of instructions
Designed to instruct the computer to execute desired
functions by the users
Introduction (cont’d)
Software Layers
System Software
•
What is system software?
Programs that
maintain operation
of computer

Two categories
Operating Systems
Utility Programs
3.1 Operating System
Operating System

What is an operating system?
– A group of programs that organize and manage the
whole computer operations
– OS is a set of instructions that coordinate all the
internal activities among computer hardware,
application programs and users
Operating System (cont’d)
• OS is controlled by the kernel.
• What is a kernel?
– Kernel is the supervisor program that manage the
memory and devices
– Kernel is loaded into the memory from the hard disk
(or other storage) during booting until computer is
turned off
– It is known as memory resident (because it resides in
memory as long as the power is on. Non-resident are
other programs that resides in hard disk at the same
time)
Operating System (cont’d)
•
The functions of an operating system
start the computer
(Booting)
provide a user interface
manage programs
administer
security
manage
memory
control a
network
provide file management
and other utilities
monitor
performance
establish an Internet
connection
schedule jobs and
configure devices
Operating System (cont’d)
• Booting

Process of starting or restarting a computer


Cold boot
Turning on
computer that has
been powered off
Warm boot
Restarting
computer that is
powered on
Operating System (cont’d)
•
A personal computer boot up process
Step 1. Power supply
Step 4. Results of POST are
sends signal to components in system unit
compared with data in CMOS chip
Step 2. Processor
on a USB drive, in floppy disk drive
or CD/DVD drive, and then hard
disk
Step 6. Kernel (core) of operating
system loads into RAM
accesses BIOS to start
computer
Step 3. BIOS runs tests,
called the POST, to
check components such
as mouse, keyboard,
and adapter cards
Step 5. BIOS looks for system files
Step 7. Operating system loads
configuration information and
displays desktop on screen
Operating System (cont’d)
• 4 main functions of OS:
– Manage computer programs
– Manage computer hardware
– Provides user interface
– Support application software
Operating System (cont’d)
• Manage computer programs
– Managing programs refers to how many users,
and how many programs, an operating system
can support at one time
– An OS can be single tasking, multi-tasking,
cooperative multi-tasking, preemptive multitasking, multithreading and multiprocessing
– Single tasking
• Runs only one program at a time
Operating System (cont’d)
– Multi-tasking
• Same concept as multiprogramming
• Allows 2 or more programs at the same time
• Divide the programs into active and inactive. Active
application is called foreground application and
inactive application is background application
• CPU does not run the programs simultaneously but
manage the resources i.e. memory based on
active/inactive applications
Operating System (cont’d)
– Cooperative Multi-tasking
• Based on multi-tasking concept, whereby
foreground application controls CPU until program
ends
• But if program crashes/hang, OS needs to be
rebooted
– Preemptive Multi-tasking
• Based on multi-tasking concept
• But if program crashes/hang, OS is able to take
over CPU so other programs can be maintained
Operating System (cont’d)
– Multithreading
• One program may execute more than one task
• Example print and edit at the same time
– Multiprocessing
•
•
•
•
Use of 2 or more processor at the same time
Programs run simultaneously
Each processor manage own resources
Hardware dependant esp. motherboard
Operating System (cont’d)
• Manage computer hardware
– Memory Unit
• OS partitions the memory for each program.
• If memory is insufficient, OS may use virtual
memory, which allocates a portion of a storage
medium to function as additional RAM
• In virtual memory, programs/instructions are
stored in fixed-sized unit called pages
• If memory if full, OS will copy pages into swap file
in hard disk and reloaded into memory when
needed
Operating System (cont’d)

With virtual memory (VM), portion of hard disk is
allocated to function as RAM
Step 1. The
operating system
transfers the least
recently used data
and program
instructions to disk
because RAM is
needed for other
functions.
Step 2. The
operating system
transfers data and
program instructions
from hard disk to
RAM when they are
needed.
Operating System (cont’d)
– Input/Output Devices
• OS provides interrupt handler, a mini program to
handle interrupt from input/output devices.
• Examples of interrupt are mouse
click/scroll/keyboard punch
• OS requires device driver to operates hardware
devices. Drivers are loaded during booting
Operating System (cont’d)
•
What is a device driver?
Program that
tells operating system
how to communicate
with device
Also called driver
Device
Driver
With Plug and Play,
operating system
automatically configures
new devices as you
install them
Operating System (cont’d)
•
Spooling


Sending print jobs to buffer instead of directly to printer
Print jobs line up in queue
Operating System (cont’d)
•
Provides User Interface
•
•
•
i.
OS manages communication between the
computers and users
Users may login, run application programs,
manage files (copy/save) and on/off computers
using any type of interface
There are 3 types of command instructions:
Command line
–
–
Instructions to be typed in i.e. to save a file into diskette
is C:\WINDOWS>copy C:myfile.doc a:
Users have to memorize instructions
Operating System (cont’d)
ii. Menu-driven
–
–
User selects instruction from a text-based pull-down
menu
Instructions are entered either via mouse click/
keyboard <ENTER> of arrow keys
iii. Graphical user interface (GUI)
–
User selects instruction by mouse click or keyboard
<ENTER> icons
Operating System (cont’d)
•
User interface

Controls how you enter data and instructions and how information
displays on screen
command-line interface
menu-driven interface
Operating System (cont’d)
• Graphical User Interface (GUI)

User interacts with
menus and visual
images such as icons
and buttons
•
Some characteristics of operating systems
Devicedependent
Runs only on
specific type of
computer
Proprietary
software
Privately owned and
limited to specific vendor
or computer model
Downward
compatible
Works with application
software written for
earlier version of
operating system
Deviceindependent
Runs on many
manufacturers’
computers
Upward
compatible
Runs on new versions
of operating system
•
Three categories of operating systems
Embedded
Network
Stand-alone
Operating System (cont’d)
Windows Version

Stand-alone operating
systems
–
Example: Windows
Year Released
Windows 3.x
1990
Windows NT 3.1
1993
Windows 95
1995
Windows NT Workstation 4.0
1996
Windows 98
1998
Windows Millennium Edition
2000
Windows 2000 Professional
2000
Windows XP
2001
Windows XP SP2
2004
Windows Vista
2006
Stand-Alone Operating Systems
• Windows XP


Fast, reliable Windows
operating system
Available in five editions:
Home Edition, Professional
Edition,
Tablet PC Edition,
Media Center Edition,
and 64-bit Edition
Stand-Alone Operating Systems
• Windows Vista

Successor to Windows XP,
containing a new interface
and new / enhanced features

Available in several editions,
grouped into Home and
Business categories
Stand-Alone Operating Systems
• Mac OS X

Available only for
computers manufactured
by Apple

Macintosh operating
system has been
model for most GUIs
Stand-Alone Operating Systems
• UNIX

Used by power users
because of its flexibility
and power

Most versions
offer GUI

Available for
computers of all
sizes
Stand-Alone Operating Systems
• Linux

Popular, free, multitasking
UNIX-type operating system

Open-source software—
code is available to
public

Both a stand-alone
and a network
operating system
Red Hat provides a version of Linux called Red Hat Enterprise
Linux.
Operating System (cont’d)
•
Network operating system

Allows users to share printer,
Internet access, files, and
programs on a network

Administers security
by establishing user name and
password for each user
Network Operating Systems
NetWare
• Examples of network
operating systems
Designed for
client/server
networks
Windows
Server 2003
UNIX / Linux
Upgrade to Windows
2000 Server
Multi-purpose
operating system
Solaris
 Version of UNIX
developed by Sun
Microsystems
 Specifically for
e-commerce
applications
Embedded Operating Systems
• Embedded operating system


Found on most mobile computers,
PDAs, and other small devices
Windows CE is
scaled-down version of Windows
Embedded Operating Systems
•
Operating systems for PDAs


Windows Mobile for Pocket PC
Palm OS for Palm
Embedded Operating Systems
•
Embedded Linux

Scaled-down Linux operating system
designed for PDAs, smart phones,
smart watches, set-top boxes,
Internet telephones, and other
devices
Embedded Operating Systems
•
Symbian OS

Open-source, multitasking operating system
designed for smart phones

Make telephone calls,
save appointments,
browse Web, send
and receive e-mail
and faxes, and more
3.2 Utility Program
Utility program
• A small program that provides an addition to the
capabilities provided by the operating system
• Performs maintenance-type tasks, usually related
to managing a computer, its devices, or its
programs.
OS Utility Program
•
File manager

Performs functions
such as copying,
renaming, deleting,
and moving files

Image viewer displays
contents of graphics
file when you double
click on it
OS Utility Program
•
Personal firewall

Detects and protects a
personal computer from
unauthorized intrusions

The latest update to
Windows XP
automatically enables
the built-in personal
firewall upon
installation
OS Utility Program
•
Uninstaller
Removes a
program and
In Windows XP,
uninstaller is in Add/Remove
all associated files
Programs in Control Panel
OS Utility Program
•
Disk scanner


Detects and corrects
problems on hard disk
Searches for and removes
unnecessary files
OS Utility Program
fragmented disk
•

Disk defragmenter
Reorganizes files and
unused space on hard
disk so programs run
faster
disk after
defragmentation
process
OS Utility Program
•
Diagnostic utility


Compiles technical information about
hardware and some software
Prepares report outlining problems
OS Utility Program
•
Backup utility

Copies selected files or
entire hard disk onto
another storage medium

Most compress files
during backup to require
less storage space
OS Utility Program
•
Screen saver

Causes monitor’s screen to
display moving image or
blank screen if there is no
activity for a specified time

To secure computer, user
configures screen saver to
require password to
deactivate
Stand-Alone Utility Programs
•
Antivirus program

Identifies and removes viruses
in memory, storage media, and
incoming files

Must be updated frequently
Stand-Alone Utility Programs
•
What is a virus?


Potentially damaging computer program
Affects computer without user’s knowledge
SIGNS OF
VIRUS
INFECTION
• An unusual message or image is displayed on the computer
screen
• An unusual sound or music plays randomly
• The available memory is less than what should be available
• A program or file suddenly is missing
• An unknown program or file mysteriously appears
• The size of a file changes without explanation
• A file becomes corrupted
• A program or file does not work properly
• System properties change
Stand-Alone Utility Programs
•
Spyware



Program placed on a computer without the user’s knowledge that
secretly collects information about the user
Often enters a computer as a result of a user installing a new program
A spyware remover is a program that detects and deletes spyware
Stand-Alone Utility Programs
•
Internet filters

Programs that remove or block certain items from
being displayed
Anti-Spam
Programs
Web
Filters
Pop-up
Blockers
Stand-Alone Utility Programs
•
File compression utility



Shrinks size of files to free up room and improve
performance
Compressed files are sometimes called zipped
files
Two popular utilities:
Winrar and WinZip
Stand-Alone Utility Programs
•
CD/DVD burning software

Writes text, graphics, audio,
and video files to a recordable
or rewriteable CD or DVD
Stand-Alone Utility Programs
•
Personal computer maintenance utility


Identifies and fixes operating
system problems and disk
problems
Some continuously
monitor computer to
identify problems
before they occur