Data - Information - Knowledge Data - Raw Facts Information - Facts organized in a

meaningful and useful fashion so as to have additional value beyond the value of the facts themselves.

Knowledge - An awareness and understanding of information and how that information can be put to best use.

Characteristics of Valuable Information

Accurate - Error free Complete - All important facts included Economical - Cost effective to produce Flexible - Usable for a variety of purposes Reliable - Can be depended on Relevant - Applicable to users purpose Simple - Only the facts that are needed

Characteristics of Valuable Information (Cont.)

Timely - Delivered when it is most useful

Verifiable - Can be checked for correctness

Reusable - Using information does not preclude using it again

Information Value Chain

Data

Information

TransformationProcess

Data

Information

TransformationProcess

DisseminationProcess

RetentionProcess

Information Resource Management

Resources can be internal or external to the organization.

Resources can be physical or conceptual.

As the scale of the enterprise grows, it becomes more difficult to manage the resources.

The principles developed to manage physical resources can be applied to conceptual resources.

Management of conceptual resources requires processes and policies for aquisition, security, quality control, disbursement and obsolescence.

Organizational commitment is required for successful management of conceptual resources.

INFORMATION SYSTEM: Hardware, software and procedures that maintain data and convert it into usable information.

Components of a Computer Based Information System

Hardware

Software

Databases

Communications

Procedures

People

I S

Functions of an Information System

Collect Process Store Retrieve Analyze Disseminate

Hierarchy of DataBit (Binary 1or 0)

Byte (Character)

Field (Attribute or Column)

Record (Tuple or Row)

File (Table or Relation)

Database

Database

A self describing collection of logically related data, organized

to meet the information needs of multiple users.

Database Management System (DBMS)

An integrated set of programs thatfacillitate the creation,access

and management of databases.

Data Organization

FilesData organized into file structures that are

typically application specific and described by data descriptions in programs

DatabasesData organized into structures that are

shared and store most of the meta-data with the data itself.

Database vs File Systems

Program 1

Program 2

Program 3

Meta-Data

Meta-Data

Meta-Data

Data

Program 1

Program 2

Program 3

Meta- Data

Data

FILE SYSTEM

DATABASE

FILE BASED SYSTEMS

Conceptual Simplicity

Easy Backupand Recovery

Fast Batch Processing

Separated and Isolated Data

Data Duplication Application

Dependent Difficult To

Represent User View

Advantages Disadvantages

DBMS BASED SYSTEMS

Integrated Data Reduced Data

Redundancy Application

Independence Easier

Representation of User View

Processing Overhead

DBMS Cost Requires

specialized IS Roles Data Contention Organizational

Conflict

Advantages Disadvantages

How Databases And DBMS Add Value

Accuracy - DBMS can enforce format rules on data entered.

Flexible - Data can easily be pulled together in a variety of fashions from different tables or files.

Economical - Information can be accessed without the cost of writing new programs.

Reliable - Modern DBMS designed for mission critical application usage.

Relevant- Data within tables or databases that is or can be viewed is tailored to specific users or applications.

Simple - Entire table or record does not need to be retrieved to access one field.

Timely - Once data is entered to the system it is immediately available.

Verifiable - Reduced data redundancy increases the ease with which data can be verified.

Reusable - Files are not constantly created and deleted in order to extract relevant data.

Centralized Vs Distributed Databases

Centralized - All data resides at a single site.

Distributed - Data is stored at multiple sites.

In both cases users usually access data through network.

Database Strategies

Stand-alone - Database and applications reside on the user’s machine. No communication with other user machines.

Centralized - Data resides on a central machine along with applications. Best example is a mainframe computer being accessed by dumb terminals.

Client/Server

Processing is divided between the user computer (client) and common computers (servers) and devices (such as printers). The intent is to allow each machine to be configured to perform it’s task optimally, allow flexibility and scalability.

Two Tiered Vs Three TieredClient/Server

Two Tiered - Both Data and Applications reside on the same server.

Three Tiered - Data and Applications reside on separate servers that are optimized for the task.

Database Servers Vs File Servers

File servers - Treats the server as simply a logical drive of the client. Data transfers are at the file or record level.

Database servers - Transfers are at the field level. Sophisticated selection is available.