Transcript MC 707 - Computer Information Systems

MP3 / MM740
Strategy & Information Systems
Module 1: Fall 2001
Tech. Overview & Fundamentals
John Gallaugher
[email protected]
www2.bc.edu/~gallaugh
Issues to be Covered
• Information Technologies & Systems
– IT vs. IS; classifications of information systems
• Hardware
– Moore’s Law & types of computers
• Software
– Operating systems & intro. to tech. competition
– What is Java & why is it important?
• Mutli-user Computing Architectures
• Data / Information
• Types of information systems
FoxMeyer
Massive System Projects
Mergers & Acquisitions
Deregulation
Globalization
The Internet
Technical Advances
Skills Crunch
5 Components of an IS
Data
Hardware
People
Information
Systems
Software
Procedures
Hardware
Computers
Peripherals
Networking Equipment
Source: Intel Corp.
The PC @ 20
2001
Dell Dimension
Processor: Intel Pentium 4,1.4 GHz
20 GB hard drive
$950
1991
Compaq 486
Processor: Intel 80486, 33 MHz
120 MB hard drive
$2,300
1981
IBM PC
Processor: Intel 8088, 4.77 MHz
Dual 160 KB floppy drives
$3,300
Storage Crib Sheet
– bit = zero or one, smallest computing unit
– byte = 8 bits, one Latin character
– kilobyte (K) = 1,024 bytes ~ 1 thousand bytes
– megabyte (MB) = 1,024 K ~ 1 million bytes
– gigabyte (GB) = 1,024 MB ~ 1 billion bytes
– terabyte (TB) = 1,024 GB ~ 1 trillion bytes
• Typical PC Capacity (9/01)
– RAM = 64 - 256 MB
– High Density (HD) diskette - 1.44 MB
– Hard Drives = 10 - 80 GB
– CDs = >620 MB
– DVD = 4.7 GB
Types of Computers
(the distinction is blurring)
• Personal / Microcomputers
– relatively compact, one primary microprocessor
– desktop, laptop, palmtop, PDA, specialized
• Mid-range Systems (Servers)
– may have more than one microprocessor,
typically multi-user & focused on a functional
area or task (marketing, plant management).
– Vintage midranges (proprietary OS): IBM
AS/400 (updated), DEC VAX (discontinued)
– Servers (UNIX/NT): Intel-based, Sun, HP, IBM
Types of Computers (cont.)
• Mainframes (IBM)
– large, expensive computer, supports multiple user
groups, terminals, run several applications at once.
– costly: support staff, air conditioning, software
– secure: centralized programs & data are easier to
backup, maintain, and monitor
• Super Computers (mfgs: IBM, Hitatchi,
Compaq)
– massively parallel and/or clustered
– used to solve problems requiring long, difficult
calculations (e.g.airline scheduling, advanced
modeling - biotech, weather, risk management)
Software
Operating Systems
Applications
Applets
Java Challenges the Paradigm
Software
Operating Systems
control hardware and provide an environment in
which applications execute
Application Programs
end-user program that performs a specific function
applications
Individual examples: word processor, spreadsheet.
operating system
Collections of apps: Office (suite), SAP R/3 (ERP)
Applets
small application programs which execute within a
larger environment (e.g. Java applets within
browser)
Competition in the OS Space
Consumer
Devices
Windows CE
Ultimate TV
Personal
Computers
Windows ME
Mutli-User
Systems
Windows 2000
MS Future
“Talisker”
XBox
Windows XP
Windows.NET
Competition
Palm (handheld) Apple
Liberate (set top)
Sony
MS Today
Unix (Sun, IBM,
HP, Compaq)
Linux
Java - a Cross-Platform Standard
• Java Consist of Two Components
– object oriented programming language
– virtual machine (software that executes Java byte
code)
• Advantages
– Write-once run-anywhere. Runs on any machine
with a JVM regardless of OS or microprocessor
– object-oriented language (reuse, faster dev.)
– secure
• Disadvantages
– 1) slow due to download times, 2) slow due to
interpreting line by line, 3) inconsistent Java VMs
Traditional Programs...
… are written for an Operating System (Windows98, Macintosh,
etc.) & compiled for a microprocessor (Intel x86, 680x0, PowerPC,
etc.). Compiled code is ready to be executed by the appropriate
microprocessor (fast).
Netscape Navigator
for Windows
DrawWindow()…
…
Netscape Navigator
for Macintosh
GetWindow()…
…
Windows
Compiler
Intel
code
10010
01001...
(code can execute on OS & processor)
Macintosh
Compiler
680x0
code
01011
00101...
PowerPC 11101
code
01110...
Java Programs...
… are written for the Java Virtual Machine (JVM). In theory, the same Java byte
code can execute on any computer with a standard JVM, regardless of OS or
processor (write once, run anywhere). Byte code is interpreted line-by-line for
each processor (slow).
(code is generic &
must be interpreted)
Java Program
Java
Compiler
OpenWindow()…
…
Windows,
Intel JVM
10110
00110...
Macintosh,
PowerPC
JVM
Sun Solaris,
Sparc JVM
01011
01100...
11000
01010...
Java byte
code
Compaq
UNIX, Alpha
JVM
01111
01100...
00010
11110...
…and more
(JVM software is
the interpreter)
Java is Often Confused With...
• JavaScript
– interpreted programming language that co-exists
in same files as HTML (doesn’t need to be
compiled into byte code)
– slower than Java
– easier to program
– supported by Netscape & Microsoft (w/some
consistency problems)
– unlike Java, can only be used to create web
pages (Java can be used to create stand-alone
applications that execute outside the browser).
Java is Often Confused With...
• ActiveX
– Microsoft's component technology architecture
(e.g. a way to string together pieces of reusable
code).
– Compiled, so it’s faster than Java, but not cross
platform.
– Unlike Java, it allows full access to the operating
system (including file access commands). This
means that ActiveX components are potentially
less-secure than Java (easier to spread viruses,
deploy malicious programs).
Multi-user Systems Architecture
• Architectures
– enable the range of technical options (and
hence business options) available to a firm
– implications regarding cost, flexibility, security
• Host / Terminal Model
• Client / Server Model
– fat clients
– thin clients
– three / n-tier model
• P2P & Grid Computing
Host / Terminal Model
All programs & data are on
the host (usually
mainframe)
Dumb terminals typically display only text sent from
host. They do not perform any computing & don’t
have a microprocessor. PCs can run terminal
programs to act like dumb terminals & access hosts.
Host / Terminal Model
• Advantages
– proven, reliable technology
– less complexity (fewer vendors)
– centralized security, version control, & backup
• Disadvantages
– costly hardware & software
– aging technology
– text-based interface difficult to use
– applications are tightly integrated with database
Client / Server Computing
• Client
– a program which makes request of another
program, usually on another computer (e.g. web
browser)
– requests data or other action from servers
• Server
– a program (usually on another computer) that runs
services that are shared among multiple
client/users on a network (ex. E-mail server, web
server, database server).
– responds to client requests (delivers data, performs
tasks)
Client / Server Model
Divide & Conquer
PC executes client code
client code makes a
request
Server executes
server code &
responds to
request, holds
data
Share & Share Alike
sales
accounting
wheels
chemicals
Client/Server
• Advantages
– easier to use (PC GUI)
– faster to develop
– database separate from applications (enables
data integration across systems & reuse)
– cheaper hardware (if PCs are in place)
• Disadvantages
– complex (multi-vendor), new technology (lowers
reliability & raises maintenance costs)
– security vulnerabilities
– version control
Variants of Client/Server
Fat Clients
client code stored
(larger files, some business logic)
client code executes
Server
(some b-logic)
Data
Thin Clients (NCs, browser apps.)
client code stored
Server
(most b-logic)
Data
client code executes
(smaller files, mostly GUI)
Three-Tier (n-tier) Architecture
client code executes
(mostly GUI)
b-logic
Server
Data
palm
back-end logic (shared or reused)
pocket pc
web
southwestairlines.com
dollar.com
Data & Information
Potentially a Key Source of
Competitive Advantage
Data, Information, & Knowledge
• Data - raw facts, figures, and details.
• Information - organized, meaningful, and
useful interpretation of data. Has a context,
answers a question.
• Knowledge - an awareness and
understanding of a set of information and
how that information can be put to best use.
• Many firms are data rich and info poor:
victims of an old or poorly planned
architecture
Examples of Data, Information, &
Knowledge
Data: raw, no context
900,000
1,200,000
1,150,000
1,100,000
Information: meaningful, has context
Quarter 1 Quarter 2
Post
900,000 1,150,000
Kellogg's 1,200,000 1,100,000
Knowledge: information above & other information
creates an awareness of impact
Post lowered its prices after the first quarter.
Price change has caused Post sales to rise at the expense
of Kellogg’s
Types/Classifications of
Information Systems
Transaction Processing Systems
(TPS)
• A shared IS that uses a combination of IT and
manual procedures to process data and
information and to manage transactions.
• Examples: Cash Registers (POS), ATM
• Characteristics:
– transactions are similar & repeatable
– support multiple users in routine, everyday
transactions (usually tactical systems)
– data capture with possible report generation
– accuracy is critical, TPS “feed” other IS
Reporting Systems - MIS
• Sometimes called Management Reporting
Systems or Management Information
Systems
• Characteristics
– use data captured and stored from TPS
– reports consolidated information rather than
details of transactions
– supports reoccurring decisions
– provides reports in pre-specified formats (on
screen, printed, or data)
Decision Support Systems (DSS)
• Allow users interrogate computers on an ad hoc
basis, analyze information, and predict the
impact of decisions before they are made. [key:
unstructured, user-led exploration]
• Characteristics
– Assists in ad-hoc decision making
– Used when requirements, processes, or procedures
are unstructured & aren’t known in advance
– Provides info needed to define & solve a problem
– Provides information in format determined at time of
need
Management Levels & IS
Strategic
Planning
Management
Control
Operational
Control
DSS
MIS
TPS
Expert Systems (ES)
• An artificial intelligence system that uses
captured human expertise to evaluate and
solve problems
• Characteristics:
– diagnoses situations and/or recommends a
course of action
– problems are structured and repeatable
– application scope is limited to a particular
problem area (domain)
Other Types of Artificial
Intelligence (AI)
• Neural Networks
– hunt for patterns in historical data
– build their own expertise based on prior history
– require clean data & consistency between
performance history and future events
• Genetic Algorithms
– search for optimal solutions based on natural
selection: (1) propose solution (2) evaluate
results against earlier solution (3) mutate &
return to step 1
Keane’s Space Truss Design