MD703Computer Information Systems

Lecture 1:Changing IS Landscape - Tech. Overview

John Gallaugher

john.gallaugher@bc.edu

www2.bc.edu/~gallaugh

Issues Addressed Today• Information Systems

– Changing IS landscape & managerial implications– IT vs. IS; classifications of information systems

• Data / Information - what’s the difference?• Software

– differences among operating systems– What is Java & why is it important?

• Hardware– What is Moore’s Law?– What are computing & architecture alternatives?

The Changing IS Landscape• Y2K (year 2000 problem)

• Globalization

• Deregulation

• The Internet

• Re-engineering

• Client/Server (architecture shifts)

• Technology Advances: Graphical User Interfaces, Object Programming, Low cost, parallel computing

• Outsourcing

So What’s An IS?

• “A combination of work practices, information, people, & information technologies organized to accomplish goals in an organization” (Alter, 1992).

• 5 components: (1) hardware (2) software/ programs (3) data/information (4) people (5) procedures

• Information Technology [IT] - technology used to create an IS.

Computer Systems

Computer Systems

Information

Procedures

Programs

Hardware

InformationSystem

InformationSystem

People

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 1,150,000 1,200,000 1,100,000

Information: meaningful, has contextQuarter 1 Quarter 2

Post 900,000 1,150,000 Kellogg's 1,200,000 1,100,000

Post lowered its prices after the first quarter.Price change has caused Post sales to rise at the expense of Kellogg’s

Knowledge: information above & other information creates an awareness of impact

Software

Operating Systems

Applications

Applets

Java Challenges the Paradigm

Software• Operating Systems

– provide an environment in which applications execute (Prosise, 1996)

• Application Programs– a program designed to perform a specific function– Individual examples: word processor, spreadsheet.

Collections of apps: Office 97 (suite), SAP R/3 (ERP)

• Applets– small application programs which execute within a larger

environment (e.g. Java applets within browser)

The OS Crib Sheet

– Win CE (pocket/palm/set-top), Win 2000, Linux

OS Processor Most likely use: Pros ConsWindows 98 Intel x86 End Users Largest number of

commercial software titles

Less stableLimited to one processor family

Macintosh OS Motorola 680x0IBM/Motorola PowerPC

Education & Artists Once considered easiest to useStable. Leader in niches

Not as much software available as Windows

UNIX Specifically designed to run on multiple processors

Servers & other multi-user systems

Reliable, highly scalable (can run on PCs to supercomputers)

Most difficult to useLittle end-user software available

Windows NT Mostly x86; limited availability on others (Compaq Alpha, MIPS, PowerPC))

Servers & other multi-user systems

More reliable than Win95Runs many Win95 programsSomewhat scaleable

Not as scaleable as UNIX(runs on fewer & less powerful machines than UNIX)

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...

Netscape Navigator for Windows

Netscape Navigator for Macintosh

Windows Compiler

Macintosh Compiler

x86code

680x0 code

1001001001...

0101100101...

1110101110...

PowerPC code

… are written for an Operating System (Windows98, Macintosh, etc.) & compiled for a microprocessor (x86, 680x0, PowerPC, etc.). Compiled code is ready to be executed by the appropriate microprocessor (fast).

DrawWindow()……

GetWindow()……

Java Programs...

Java Program Java Compiler

Windowsx86 JVM

0001011110...

… 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).

OpenWindow()……

MacintoshPowerPC

JVM

Macintosh 680x0 JVM

Digital Alpha UNIX

JVM

...

Java bytecode

1011000110...

0101101100...

1100001010...

0111101100...

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).

Hardware

Computers

Peripherals

Networking Equipment

Moore’s Law

Moore’s Law

Measuring Storage Capacity– 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 (1/99)– RAM = 32 - 128 MB– High Density (HD) diskette - 1.44 MB– Hard Drives = 4 - 12 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, H-P, Compaq Alpha, IBM RS-6000

Types of Computers (cont.)• Mainframes (leading mfgs: IBM, Hitatchi)

– 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)– massively parallel (multiple processors)– used to solve problems requiring long, difficult

calculations (e.g.airline scheduling, weather prediction)

Leading IT Architectures forMulti-user Computing

• Host / Terminal Model

• Client / Server Model– fat clients– thin clients– NCs - network computers

• Architectures– enable the range of technical options (and

hence business options) available to a firm– implications regarding cost, flexibility, security

Host / Terminal Model

Dumb terminals 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.

All programs & data are on the host (usually mainframe)

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

PC executes client codeclient code makes a

request

Server executes server code & responds to request, holds data

sales

accounting

wheels

chemicals

Divide & Conquer

Share & Share Alike

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 Clientsclient code stored

(larger files, some business logic)client code executes

Server(some b-logic)Data

Thin Clients (NCs, browser apps.)client code executes

(smaller files, mostly GUI)

client code storedServer(most b-logic)Data

Three-Tier (n-tier) Architecture

client code executes(mostly GUI)

ServerData

b-logic

NC (Network Computer)• Advantages

– lower cost of ownership (centralized administration/ version control, reduced complexity, tighter security)

– GUI ease of use– application & data separate– Most appropriate for high structure & control environments.

(Ex. Delta Airlines, GM, HomeDepot)

• Disadvantages– inappropriate for unstructured tasks– not portable (yet)– slow & unproven, currently few choices

Yearly Cost of Ownership

Source: Gartner Group

$0

$2,000

$4,000

$6,000

$8,000

$10,000

$12,000

Windows NC

Types/Classifications ofInformation 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 (Senn).

• 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