INFORMATION TECHNOLOGY Flashcards
Define information systems
system
processes data and transactions
to provide users with information
to plan, control and operate an organization
Process of information systems
Collect data Input into the system Process data Provide users with information Control process
Types of IT
DEMMOTE
Decision support Expert Management reporting Management information Office automation Transaction processing Executive information
Define office automation system
computerized system
support daily work of employees
improve productivity
word processing
excel
Transaction processing system
daily processing of transactions
- airplane reservations systems
Management reporting
helps in decision making
Management information
provide past, present, future information
for planning, organizing and controlling the operations
Decision support systems
combine models and data
to resolve non-structured problems
with extensive user involvement
Expert systems
apply reasoning methods to data
to render advice like a human expert
Executive information
supports executive work
Two distinct roles of info system
- recording transactions
2. support for decision-making
What is systems design
design of business processes
for effectiveness and efficiency
Steps in systems development life cycle
PADD TIM
Planning Analysis Design Development Testing Implementation Maintenance
THE PLANNING PHASE #1 PSSPF
Problem - identify System - what to be developed? Scope Plan - develop project plan Initial feasibility - evaluate
Planning phase
How to define the system to be developed?
Identify
Select - system to be developed
based on strategic goals of the organization
Planning phase
How to determine the project scope? BEAD
Boundaries - set project’s boundaries
Achievement - what can the new system do?
Evaluation process - how?
Document -create the project scope document
- description of the scope
Scope may be revisited or revised during the process of systems design
Planning Phase -
How to develop a project plan?
Activities - define activities to be performed
Resources - Individuals and resources to be used
Dates and Milestones
- start, end, and milestone dates
for the activities to be performed
what activities?
what resources are needed?
when?
What is a project plan?
plan that defines:
- activities that will be performed
- individuals and resources that will be used
- establish milestones for activity performance
Difference between project scope and plan
Scope - what the project will do? its boundaries? understand the new system, how to evaluate it
Plan - activities, who will perform, what resources to use and milestones
Initial feasibility of the project
Initial Evaluation
Determine the project's:
technical
organizational
economic feasibilityANALYSIS PHASE #2
Team determines system requirements:
Needs Assessment
Gap Analysis
Requirements Definition Document
Systems Specification Document
Composition of Team in Analysis Phase
Team composed of:
end users
technology specialists
systems analysts
process design specialists
Purpose of team analysis
to understand the requirements
of the proposed system
What is needs assessment?
During analysis phase
determines the system requirements
in terms of:
processes
data capture
information and reporting
What is gap analysis?
Examines the difference
proposed vs existing system
What is requirements definition document?
establish priorities for the gaps
receive sign-off from end users
What is system specification documents?
Contain information on the basic requirements:
performance levels reliability quality interface security and privacy constraints and limitations functional capabilities data structures and elements
THE DESIGN PHASE #3
Goal is to build a technical blueprint of how the proposed system will work.
Design the components of the system
Components of the systems design
DURIP
database user interface for input and output required reports infrastructure and control programs
THE DEVELOPMENT PHASE #4
- transform documents
from design phase into the actual system - build the system platform -
built or purchased off the shelf - customize the platform
- develop the database
THE TESTING PHASE #5
- verify if the system works
- if it meets the system requirements
as defined in the analysis phase
Four kinds of testing
unit testing
system testing
integration testing
user acceptance testing
What is unit testing?
test pieces of code
What is system testing?
testing of the integration of
units or pieces of code into a system
What is integration system testing?
test whether separate systems can work together
What is user acceptance testing?
test if the system meets business requirements
test if it enables users to perform their jobs efficiently and effectively
THE IMPLEMENTATION PHASE #6
putting the system in operation by the users
provide detailed user documentation
train users
use different implementation methods
Implementation Methods
parralel implementation
plunge implementation
pilot implementation
phased implementation
Parallel implementation
use both systems until new system is operating properly
full operational test of new system while old system is in use
less risk of system disaster
disadvantage - additional work and double in cost
Plunge implementation
stop using the old system and use new system immediately
less costly but risky
Pilot implementation
small group of individuals using the new system until sure that its working properly
partial operational test at lower cost than parralel
and less risk
Phased implementation
install the system in a series of phases
THE MAINTENANCE PHASE #7
monitoring and supporting the new system
ongoing training
help desk resources
system of making authorized and tested changes to the system
General components of IT system
computers
hardwares
software
Types of Computers
supercomputers mainframe computers servers microcomputers tablets/smart phones/personal digital assistants
Types of hardware
CPU
secondary storage
input devices
output devices
Types of software
systems software
applications software
Methods of processing
batch or online real time
centralized/decentralized/distributed
Methods of data structure
data organization for computer operations
data file structure
Supercomputers
extremely powerful
high speed
for extremely high volume and complex processing
Mainframe computers
large, powerful, high speed
less powerful than supercomputers
for high volume transaction processing needs
clusters of lower cost powerful servers
Servers
high powered microcomputers
serve applications and data to clients
clients connected via network
greater capacity than clients microcomputers
central repository for organizational data
virtual machine
Virtual machine
multiple operating systems coexist and operate simultaneously on the same machine
lower hardware costs and increased energy savings
Microcomputers
desktop
laptop
personal computers
designed for one person use
CPU
the principal hardware component
major function:
fetch stored instructions and data
decode instructions
carry out the instructions
Functions of CPU
fetch stored instructions and data
decode instructions
carry out the instructions
Components of CPU
arithmetic/logic unit
primary memory (storage)
control unit
Arithmetic logic unit - cpu component
performs mathematical operations and logical operations
Primary memory/storage - cpu component
active data and program steps being processed by the cpu
RAM - random access
ROM - read only
RAM
stores application programs and data
at execution time
Control unit - cpu component
interprets program instructions
coordinates input, output and storage devices
Secondary storage
magnetic tape magnetic discs RAID - redundant array of independent discs compact discs solid state drives SSD cloud based storage
Magnetic tape
slowest type of storage
data stored sequentially
used for archiving purposes
Magnetic discs
most common storage
hard discs
hard disk drives _HDD
data can be accessed directly
RAID
redundant array of independent
store same data redundantly in multiple magnetic discs
in original recording, data is written to multiple discs
if a disc fails, another one is available
Compact discs
CD DVD
same size
both use optical technology to read and write data
SSD solid state drive - USB, thumb drives, flash drive
use microchips to store data
use usb interface to plug
don’t require moving parts for read and write operations
faster and more expensive per gb than cd and dvd and hdd
used for auxiliary storage
Cloud based storage - SAAS
called storage as a service
hosted offsite by third parties
accessed via internet
Manner of Representation of information
digital
analog
Digital
represents information by series of binary digits 0s and 1s
bit - one binary digit
byte - series of bits, can be a letter, number
Analog
produced by fluctuations of a continuous signal - speech, temperature, weight, speed
does not use 0s and 1s
uses electrical, mechanical, hydraulic, pneumatic devices to transmit fluctuations in the signal
Online
equipment in direct communication with cpu
connection with internet
Off line
equipment not in direct communication with cpu
no internet connection
What is a Console
terminal used for communication between operator and computer
What is Peripheral equipment
all non cpu hardware under the control of cpu
can be online or offline
input, storage, output, communication
What are Controllers
hardware units used to operate input output units
Waht is Buffer
temporary storage unit used to hold data during computer operations
What is MIPS
millions of instructions per second
unit of measuring the execution speed of computers
Types of Input Devices
keying data - key to tape or key to disk
online entry
turn around documents
automated source data input devices
electronic commerce and electronic data interchange
electronic commerce
electronic data interchange
Kinds of automated source data input devices
magnetic tape reader magnetic ink character reader scanner auto teller machine radio frequency identification RFID POS recorders point of sale voice recognition
What is Key to tape or key to disk?
data is entered on magnetic tape or disk then read into a computer
Types of Online entry
- visual display terminal/monitors
- mouse, joystick, light pens
- touch sensitive screen
Types of visual display terminals/monitor
uses keyboard to directly enter data into computer
input interface
graphical user interface
command line interface
What is input interface?
program that controls the display for the user and allows the user to interact with the system
What is graphical user interface?
GUI
uses icons, pictures, and menus instead of texts for inputs
What is command line interface?
uses text type commands
Turnaround documents
documents sent to the customer and returned as inputs
Magnetic tape reader
device capable of sensing information recorded as magnetic spots on magnetic tape
Magnetic ink character reader
MICR
reads characters that have been encoded with a magnetic ink
Scanner
device that reads characters on printed pages
ATM
machine used to execute and record transactions with financial institutions
RFID radio frequency identification
uses radio waves to track and input data
for inventory systems, contactless payment systems
RFID tags can be read wirelessly by RFID readers
dos not require line of sight access or barcode
example - speedpass toll collection
POS
device that reads price and product code data
functions as terminal and cash register
can record, track customer orders, process debit credit cards
Electronic commerce and electronic data interchange
one company’s computer communicating with another company’s computer.
ex. buyer sending a purchase order to supplier
Plotter?
an output device that produce graphs
COM - computer output to microfilm or microfiche
uses photographic process to store output
Components of system software
Operating system
Utility programs
Communications software
What is an operating system?
Windows, linux, unix
Manages the input, output, processing, storage devices and operations of a computer
What is a utility program?
handles common file and data manipulation and housekeeping tasks
What is a communications software?
controls and supports transmission between computers, monitors and databases
Applications software?
programs designed for specific applications :
word processing, spreadsheets, email, database systems
Types of accounting software
low end
high end
ERP
Low end accounting software
all in one package - designed for small businesses
High end software
set up in modules like Sage 100
ERP
enterprise resource planning
complete info system for large and medium size organizations
SAP, Peoplesoft, Oracle and JD Edwards
Advantages of ERP
integration of various portions of the information system
direct electronic communication with suppliers and customers
increased responsiveness to information requests for decision making
Disadvantages of ERP
complexity
expensive
difficult integration with supplier and customer
Compiler?
Produces a machine language object program from a source program language
What is multiprocessing?
simultaneous execution of two or more tasks, two or more cpus
What is multitasking?
simultaneous processing of several jobs on a computer
What is object program?
converted source program that was changed using a compiler to create a set of machine readable instructions that the CPU understands
Generations of source Source programming
program written in language form from which statements are translated into machine language
Machine language
Assembly language
High level programming language - java, c++, cobol
Application specific language
Visual or graphical interface compiled with 3rd or 4th generation compiler
Assembly language?
low level programming language that uses words instead of numbers (mnemonics) to perform an operation
assembly language must be translated to machine language by a utility progam called an assembler
Assembler?
translates assembly language to machine language to perform an operation
Machine language?
uses combinations of 1s and 0s language
Compiler?
produces a machine language object program from a source program language
High level programming language?
are object oriented programs
Object oriented programs?
based on the concept of an object keep together data structures and method thru encapsulation uses the concept of a class and inheritance
Object?
data structure that uses a set of routines
Methods?
set of routines used by the data structure
Class?
set of objects with similar structures
Inheritance?
ability to create new classes from existing classes
classes - set of objects
Application specific language
Query style
built around database systems
closer to human languages
Visual or graphical interface?
creates source language usually compiled by 3rd or 4th generation compiler
Virtual memory storage?
like icloud
online secondary memory used as an extension of primary memory
Protocol?
rules determining the required format and methods for transmission of data
Desk checking
review of the program by the programmer for errors before the program is run and debugged on the computer
Debug?
find and eliminate errors in a program
Edit
correct input data before processing
Loop
set of program instructions performed repetitively a predetermined number of times or until all of the data are processed
Memory dump
listing of the contents of the storage
Patch
section of coding inserted into a program to correct a mistake or alter a routine
Run
complete cycle of a program - input, processing, output
Batch?
groups of like transactions, leaves easy to follow audit trail
Online Real time or Direct access processing
transactions are processed in the order by which they occur
can be online transaction processing or
online analytical processing
OLTP - Online Transaction Processing
ex. airline reservation system, atm
supports day to day operations
OLAP - Online Analytical Processing System
enables the user to query the system - retrieve data, conduct analysis
used for analytical analysis
THE OLAP SYSTEM
- Uses graphical and statistical tools to view and analyze data (multidimentional)
- Used as decision-support systems
- periodically downloads and combines operational databases into a data warehouse or data mart
- Artificial intelligence - software designed to help humans make decisions
- Expert system - form of artificial intelligence that guides decision processes within a well defined area and allows decisions comparable to those of an expert
What is the process of artificial intelligence?
- Software designed to help humans make decisions
- Models aspects of human thought on computers
- Deals with decisions made using relatively structured approach
- Quickly solves a problem that a human could ultimately be solved through extremely detailed analysis
What is the process of expert system?
- form of AI
- Guides decision processes within a well-defined area
- allows decisions comparable to those of an expert
- Expert knowledge is modeled into a mathematical system
Decision Support System?
Computer based information system combine models and data in an attempt to solve relatively unstructured problems with extensive user involvement
Data warehouse?
a subject-oriented integrated collection of data used to support management decision-making processes
Data mart?
a data warehouse that is limited in scope
Data mining?
sophisticated techniques from:
statistics
artificial intelligence and
computer graphics
to explain, confirm and explore
the relationships among data(in data mart or data warehouse)
Methods of processing
- Batch or online real time
2. Centralized, decentralized, or distributed
Centralized processing?
Processing in one location
Mainframe computer processes data submitted to it through terminals
Decentralized processing?
Processing and storage of data at multiple locations
Computers are not interconnected by a network
Users at various sites cannot share data
A collection of independent databases, not single database
End user computing is decentralized
Distributed processing
Transactions for a single database
processed at various sites
Processing may be batch or online real time
Overall single database is ordinarily updated for these transactions and available at the various sites
