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Review For Final
© Abdou Illia
(Spring 2009)
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Computer Hardware
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The Core Computer Components Three subsystems in a computer system:
1. Input subsystem2. Processing subsystem3. Output subsystem
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Output Devices Monitors
Cathode ray tube (CRTs) Liquid crystal displays (LCDs) Quality of display
Resolution in pixels (e.g. 640 x 480) Dot pitch in millimeters (.26 to .28) Active-Matrix vs. Passive-Matrix display
Touch screens Input and output via display device
Monitor size Common resolution
15 inches 640 x 480
17 inches 800 x 600 or 1024 x 768
19 inches 1024 x 768 or 1280 x 1024
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Printers Speed and resolution
Pages per minute (PPM) Dots per inch (DPI)
Number of ink dots to fill a square inch Higher DPI = greater page clarity
Impact printers Create image by striking paper and ribbon Dot-matrix printers = most common impact printers
Non-impact printers Create image by spraying or rolling ink on the page
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I/O devices or Secondary Storage Nonvolatile storage of digital data Magnetic or optical Magnetic storage (Floppy disk, Magnetic
tape, Zip disk, Hard disk) Sequential access (tape) or direct access (HDD) Hard disk drives
Two main standards: IDE (Integrated Drive Electronics) aka ATA (AT Attachment) SCSI (Small Computer System Interface)
SCSI allows disk fault-tolerance through RAID – Redundant Array of Inexpensive Disks
Disk speed: Transfer rate in MBps (Megabytes per second) Average Read Time (in milliseconds or ms) Platter rotation speed in RPM (5400/7200/10,000/15,000)
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Measuring Storage Capacity
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Processing subsystem Two major components
CPU (Central Processing Unit) or Processor(s) Primary Storage:
Random Access Memory (RAM) Read Only Memory (ROM)
CPU
Primary Storage
Busses that transfer data
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Central Processing Unit
Clock: generate time that synchronize other components
ICU: Fetches instructions from RAM
ALU: Execute instructions (arithmetic & logic operations)
Registers: Store control information, data, intermediate results
Processor
Clock
Instruction Control Unit
Arithmetic Logic Unit
Registers
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CPU speed Speed measured in hertz
Hertz = # of instructions executed per second Megahertz = 1 million of instructions per second Gigahertz = 1 billion of instructions per second
Intel- Celeron
- Pentium 3, Pentium 4, Pentium 4 Xeon, Dual Core
Advanced Micro Devices (AMD)
- K6 series processors (which compete with Intel Pentium 3)
- Athlon series (which compete with Intel Pentium 4)
IBM
- PowerPC 740, 750, 750FX, 750GL, 750GX
Major Processor manufacturers
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Primary Storage
RAM holds running programs and the data they use
ROM contains critical programs such as those that boot the computer
Primary Storage
RAM
ROM
Computer’s memory stored on semiconductor chips Two categories:
RAM (Random Access Memory) which is volatile Synchronous Dynamic RAM (SDRAM) Double Data Rate SDRAM or DDR SDRAM
ROM (Read-Only Memory) which is non-volatile
Capacity in Megabytes (MB) or Gigabytes (GB)
Program Data
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Summary QuestionsBook Notes
1) Name two devices that could be used for both input and output.
2) What is the difference between: (a) a Kilobyte and a Gigabyte? (b) a Megabyte and a byte?
3) What is the function of the Instruction Control Unit or ICU found in the processing subsystem?
4) Explain the difference between RAM and ROM.
5) What is pixel? What is dot pitch
6) What is a byte?
7) What is a Hertz?
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Network Technology
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Computer Network An interconnection of computers and
computing equipment using either wires or radio waves over small or large geographic distances
“Connect to GHI”ABC
DEF GHI
JKLMNO
Once connected to the network, the computer (or another device) becomes a network node
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Transmission Media Physical media
Transmission media used to physically connect nodes in to the network
Transmits electrical or optical signals Could be cooper wire or fiber optic cable
Physical
Wireless
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Transmission Media (Continued) Twisted Pair
Category Use Signal Data rate Distance Problem
Category 1 Telephone Analog/Digital <100Kbps 3-4 miles Security, noise
Category 2 T1, ISDN Digital <2 Mbps 3-4 miles Security, noise
Category 3 LANs Digital 10 Mbps 100 m Security, noise
Category 4 LANs Digital 20 Mbps 100 m Security, noise
Category 5 LANs Digital 100 Mhz 100 m Security, noise
Category 6 LANs Digital 250 Mhz 100 m Security, noise
Category 7 LANs Digital 600 Mhz 100 m Security, noise
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Wireless Media Uses electromagnetic waves or electromagnetic radiation for
data transmission Propagation through space, and indirectly, through solid objects Two kinds of wireless media used
Radio waves (radio Frequency) Affected by Multipath interference Highly vulnerable to snooping Limited distance Blocked by thick objects
Infrared light Close proximity and “line of sight” location required
LaptopComm. Tower
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Network Topologies The configurations of network components
How physically the network looks like How logically data is transferred on the network
Widely used network topologies: Bus Star Ring (Mesh, not common in business setting)
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Bus Network Topology Most simple network topology All devices connected to a common central
cable called a “bus” Inexpensive If cable fails, the entire network will shut
down
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Star Network Topology Centered around
central device called a hub or a switch
All network nodes connect to the hub/switch
Easy to install and update
If hub fails, network fails
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Ring Topology
Node connected to a logical ring in a central device called MAU
More reliable than bus or star Only one node sends at a
time (no collisions)
Expensive and limited speed
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Network Architecture
Defines how the processing takes place on the network
Two primary types Client-server Peer-to-peer (P2P)
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Summary Questions
Malaga Notes
1) What is a node?
2) Name physical and wireless media used in networking
3) What transmission media is used for the telephone?
4) What are the main network topology? What are the differences between them?
5) Distinguish between Client-server and P2P networks
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The Internet and eBusiness
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Brief history of the Internet
1969 The Defense Advanced Research Projects developed ARPANET, the precursor of the Internet
1971 Ray Tomlison invents e-mail
1979 USENET newsgroups created at Duke University and the University of North Carolina
1984 Domain Name System (DNS) established
1991 Tim Berners-Lee creates the World Wide Web
1994 First online shopping mall, first spam email, first pizza ordered online, first advertisement banner
2000 A major denial of service attack brings down websites such as Yahoo!, Amazon.com, and eBay
2002 Denial of service attack knocks out 8/15 root DNS servers
Make sure you know what DNS is used for.
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Webserver needs:- Network (or Server) Operating System- TCP/IP- Domain name (e.g. eiu.edu)- Internet access - IP Address (e.g. 139.67.8.3)
User PC needs:- Workstation Operating System- TCP/IP- Web browser (e.g. Internet Explorer)- Internet access (e.g. thru an ISP)- IP Address (e.g. 128.150.50.9)
Accessing the Internet (www)
NetworkWeb
Browser
Packet
Router
Packet
Route
WebserverSoftware
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Internet applications/services E-Mail File transfers Instant messaging (IM) Newsgroups Streaming audio and video Internet telephony World Wide Web (WWW) Portal
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Intranets and Extranets Intranet
Internal company network that uses Internet and WWW technologies.
Typical Use: Finding and sharing work documents Collaboration between employees to work in teams Communication tool
Typically, only internal employees can get access
Extranet Web site that allows customers and business
partners limited access to organizational intranet Uses Internet and WWW technologies Add additional security through the use of a
Virtual Private Network (VPN)
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Portal Portal
Web site that offers a broad array of resources and services; such as
email newsgroup Serach engines Online shopping malls
Example: yahoo!, msn, aol
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Summary Questions
Refers to the slide # in class posted notes
Book Notes
1) (a) Name some Internet applications/services (b) What is Instant Messaging?
9,14,
2) (a) What does a user PC needs for accessing the World Wide Web? (b) What is needed on the webserver side?
7
3) Name some Internet connection options available for residential users and businesses.
5-6
4) (a) What is an intranet? (b) an extranet? 18,19
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Information Systems for
Business Integration: ERP Systems
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Business Integration?
SalesDepartment
LogisticsDepartment
ProductionDepartment
HorizontalIntegration
Vertical
Integration
Suppliers
Customers
Q: what is meant by horizontal business integration? Vertical?
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Systems for Horizontal Integration
Enterprise Resource Planning (ERP) systems integrate all the internal processes through a common
information system (or an integrated set of info systems)
ERP system
SalesDepartment
LogisticsDepartment
ProductionDepartment Warehousing
MarketingDepartment
AccountingDepartment
Process1 Process2Process1 Process2
Process1 Process2 Process1 Process2
Process1 Process2 Process1 Process2
CommonDatabase
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ERP Components (or Modules) Two types of components
Core ERP Components Extended ERP Components
Core ERP Components Traditional components found in most ERP systems They primarily focus on internal operations
CommonDatabase
Finance &Accounting
Manufacturing*
* Also called Production & Material Management
* Helps from new products development to actual production
* Handles demand forecasting, production planning, production scheduling, quality control, etc.
HumanResource
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ERP Components (or Modules) Extended ERP Components
Extra components that might be included They primarily focus on external operations
CommonDatabase
CustomerRelationshipManagement
SupplyChain
Management
BusinessIntelligence1
E-Business2
1 Provide information that help users in decision-making
1 Collects info used throughout the organization, organize it, and uses analytical tools to help decision-making process
2 Includes e-logistics (managing transportation & storage of goods over the Internet) and e-procurement (B2B purchase & sale of supplies & services over the Internet)
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ERP Components (or Modules) ERP mainly used by medium and large businesses
Average lifetime cost: $15 Million (2003 surveys) Implementation process: up to 5 years
The largest vendors worldwide in 2005 according to Gartner Dataquest
# Vendor Revenue(million $)
Market share(%)
1 SAP 4726 28.7
2 Oracle Applications* 1674 10.2
3 The Sage Group 1221 7.4
4 Microsoft Dynamics 616 3.7
5 SSA Global Technologies 464 2.8
* In January 2005, Oracle bought PeopleSoft the 3rd player until then.
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Factors in ERP System Success Active support of upper management Having the best people on the
implementation team Managing the time line well User involvement in the planning and
implementing ERP systems
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Summary QuestionsBook Notes
1) What is the difference between Horizontal integration and Vertical integration? What could be the consequences of a bad horizontal integration?
5,6
2) What kind of information system is typically used by organizations for horizontal integration?
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3) What are the core modules found in ERP systems?.? 10
4) What does the Manufacturing ERP component allow? Name some of the activities it handles
10
5) Name the major three ERP software vendors 12
6) What are the success factors of ERP implementation? 14
Refers to the slide # in class posted notes
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Information Systems for
Business Integration:
EDI, SCM, CRM Systems
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Supply Chain Management SCM
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Supply Chain Supply Chain includes parties involved in the
procurement of product or raw material Upstream parties Downstream parties
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Supply Chain Management SCM SCM implies the management of
information flow between a company and upstream and downstream parties of the supply chain
Which of the following is NOT a potential benefit of SCM?
a) It helps avoid shortage of raw materialb) It could shorten the time for delivering finished
products to distributorsc) It could help organizations better forecast their
production of goods and servicesd) It could help organizations better forecast the needs of
their distributorse) None of the above
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SCM Process Stages of SCM (SC Council’s Reference Model):
1) Planning: develop and implement processes that attempt to forecast demand for products and services
Goal: Balance demand with supply of raw material
2) Sourcing: determine who should supply the items required
Goal: Be supplied on time, within budget
3) Production: make the product1) Schedule production
2) Ensure raw materials are on hand when needed
4) Product delivery (logistics) 1) Everything from receiving a customer inquiry to invoicing
2) Warehouse management is one very important factor
5) Returns: managing returns of raw materials as well as finished goods
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EDI: a SCM Technology Electronic Data Interchange (EDI):
A network technology that allows the transfer and processing of business documents (usually orders) between a company and its suppliers
Suppliers
Company’s Internal processes
SalesDepartment
Process1 Process2
DeliveryDepartment
Process1 Process2
ProductionDepartment
Process1 Process2
EDI System
Value Added Network (VAN)or
Private network connection
EDI Sys.
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EDI: SCM Technology EDI documents must be formatted according
to specific standards ANSI X12 – used in North America EDIFACT – international, but widely used in Europe
Advantages: Eliminates paperwork Reduces errors Speeds supply process
Disadvantages: Provides connection only between two companies Limits freedom of comparing prices.
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SCM information system Part of extended ERP components Could be bought separately
Company’s Internal processes
SalesDepartment
Process1 Process2
DeliveryDepartment
Process1 Process2
ProductionDepartment
Process1 Process2
SCM System
Network connection
Suppliers
SCM Sys.- Forecast demand- Handle purchase of supply- Manage storage + shipping
Three main functions
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Customer Relationship Management CRM
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CRM systems CRM systems are systems that can help
manage all aspects of organizations’ relation with their customers.
Which of the following is NOT a potential benefit of CRM systems?
a) Provide better customer serviceb) Make call centers more efficientc) Help sales staff close deals fasterd) Simplify marketing and sales processese) Discover new customersf) None of the above
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Goals of CRM systems Goal of CRM is to increase sales and repeat business
by learning the customer Determine the customer’s needs and preferences Determine the customer’s satisfaction with service Determine which customers are in the magic 20 percent (or
have the potential to become part of it)
Recency, Frequency, Monetary value (RFM) at heart of CRM systems How recently a customer purchased items (Recency) How frequently a customer purchased items (Frequency) How much a customer spends on each purchase (Monetary
Value
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Summary QuestionsBook Notes
1) Is the information flow between a company and its retailers part of its supply chain?
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2) What are the potential benefit of SCM systems? 7
3) What are the 5 stages of SCM according to the SC Council’s Reference Model?
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4) What is EDI? What kind of network connections are usually used in EDI? What is the EDI message standard used in the U.S.?
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5) Are SCM systems part of ERP systems? Are SCM systems sold as separate system from ERP systems? 11
5) What are the potential benefit of CRM systems? 14
5) What is the main goal of using CRM systems? What is meant by RFM?
15
Refers to the slide # in posted class notes
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Managing Security
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Best way to prepare Review the ppt notes or chapter 4 in the
book to make sure you can answer the following questions Chapter 4 Review Questions available in the
Review section of course web site
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Managing the Development and
Purchase of IS
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Systems Development Methodology? The process companies go through to
develop and maintain an information system Framework for successful IS development A System Development Methodology is used
For building a new system Or for modifying an existing system
Examples of SDM: System Development Life Cycle ￭ Prototyping Joint Application Development ￭ Rapid Application Development
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Questions Which of the following is true about SDM?
1) They provide guidelines for developing IS and maintaining them which includes upgrading and improving them.
2) SDM are needed when a brand new IS has to be developed, but you don’t need to use a SDM when it comes to modifying an existing IS.
3) When a company is engaged in developing an IS, the process involves the company’s employees who would be the future users of the IS, and IS professionals like system analysts and programmers. But it doesn’t involve the company’s management
4) All of the above
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Traditional Systems Development Life Cycle (SDLC)
Seven phases 1) Planning 5) Testing2) Systems Analysis 6) Implementation3) Systems Design 7) Maintenance4) Development
Typically one phase needs to be completed before beginning the next
Problem in later phase may require return to previous phase
Planning
Analysis
Design
Development
Testing
Implementation
Maintenance
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Question
In SDLC, the 7 phases are typically followed in a sequential order, which means we don’t return to a previous phase in any circumstances
True False
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Planning Feasibility analyses
Technical Analysis Do the technologies exist to develop the system?
Economic Analysis Can the organization afford the system? Will it provide an adequate Benefit?
Operational Analysis (i.e. assessing the human element of the proposed system)
Resistance to change Organizational politics
System development schedule Is the proposed development time line realistic? Is the programming team available during Programming
step? Planning performed by Project Manager using
Search and investigation (e.g. for technical analysis step) Total Cost of Ownership analysis Project Management software
Feasibility Analyses
System Development Schedule
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Systems Analysis Systems analyst works with company to understand
the problem fully and to detail the requirements of the proposed system
Step 1: Analyze current system Objectives:
Understand what things are done and how (business processes) Identify any problems associated w/ current business processes
Techniques: Observe employees at work Talk to employees (potential users) Conducting interviews
Analyze current system
Define new system requirement
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Systems Analysis Step 2: Define new system’s requirements
Main Objective: Specify What need to be done (not how to do it)
To be defined: Input requirements (nature of data, source, etc.) Processing requirements Output requirements (Types of reports, content, etc.) Storage requirements
Tools and techniques Data flow diagrams (DFD)
Start with high level process Add more levels with increased levels of detail
Computer-Aided Software Engineering (CASE) tools Software that eases the systems development process
Analyze current system
Define new system requirements
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Data Flow Diagrams (DFD)
Data flow
Process
External Entity
Data storage
. Symbolized by an arrow.
. Shows data being passed from or to a process
. Symbolized by a rectangle or a curved rectangle.
. Action performed by people of organizational units in order to transform input into output OR Action performed by people in the organizational units to help the units achieve their objectives
Symbolized by a square, an external entity is something (person, group, department, etc.) outside the system that interacts with the system by providing input or receiving information.
Used to store data in the system. Represents a file, a database, etc.
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Systems Design Using the requirements from Systems Analysis phase
to design the new or modified system. Logical systems design
Details the system’s functionality (what it should do?) Uses Structure charts to create top-down representation of
system’s modules Uses System flowcharts to show relationships between modules
Physical systems design Specifies all of the actual components (hardware, network, etc) used
to implement the logical design The design must be frozen at end of this phase to prevent the
to system grow indefinitely in terms of its scope and features Scope creep Feature creep
Performed by system designer or (system analyst in some case)
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Development Programming process is usually the most
difficult and time consuming in the Development process.
Development performed by programmers, database developers, and network engineers
Programmers use Program Development Cycle
1) Review the input, processing, output, and storage requirements2) Develop the logic of the programs (using Flowcharts and Pseudo code)3) Write the programs using code generators & programming languages4) Test and debug the programs5) Complete the programs documentation
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Development tools
Program Flowchart:
Graphical illustration of the problem-solving logic
within a programPseudocode:
English-language statements that describe the processing steps of a
program in paragraph form.
Programming languages:-Java-C++-Visual Basic-Etc.
Code generators:Software that generate programs that programmers could modify.
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Testing Programmers test modules
Do they return proper outputs? Do they handle incorrect data appropriately?
Development team do unit testing i.e. testing how modules work together
System testing (software along with database and network component)
Verification: Testing system in simulated environment with simulated data
Validation: Testing system in real working environment with real data
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Implementation Implementation strategies
Direct cutover: Quick change to new system
Parallel conversion: Old and new systems used in parallel for a while.
Pilot testing: New system installed at only one location or one department
Staged conversion: Only one part of the system installed, then another part is installed.
User training
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Maintenance Maintenance counts for as much as 80%
of the total cost of an information system Tasks
Correct errors found during implementation System enhancements
Incremental upgrades Addition of major new features
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Summary QuestionsBook Notes
1) What is a System Development Methodology? What is it used for?
2) What are the 7 phases of the SDLC methodology?
3) What kind of Feasibility analyses need to be performed during the Planning phase? Why is the system development schedule important?
4) What are the two steps in the Systems Analysis phase? What techniques and tools are used during the Systems Analysis phase?
5) What tools do programmers usually use during the Development phase?
6) What is the difference between the Verification and the Validation tests performed during systems testing?
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SDLC: RecapSteps Key actors Tools/Techniques
1. Planning Project Manager Project Management software, Total Cost Ownership analysis, etc.
2. System Analysis System Analyst, Users. Interviews, observing users at work, DFD
3. System Design System analyst (or system designer)
System Flowchart, Structure chart
4. Development Programmers, database developers, network engineers
Program Flowchart, Pseudo code, programming languages, DBMS
5. Testing Development team, Users Unit testing, verification, validation
6. Implementation Development team, Users Direct cutover, parallel conversion,pilot testing, staged conversion
7. Maintenance internal IS staff, external consultant
Make sure you can answer questions about System Development (see SDM Quest link in Review section)
