IT_Chapter_12A

Purpose of Information Systems

• Information systems

– Collects, stores and organizes information

– Retrieves value from data

– Harness many types of data

– Computer’s reason for existence

• Components of an information system

– Physical means of storing information

– Procedures for ensuring data integrity

– Rules regarding data use and distribution

– Means of distributing the data

– Tools to organize the data

Types of Information Systems

• Office automation systems

– Performs various office tasks

– Allows users to efficiently handle data

– Tedious tasks become simple

– Built using off-the-shelf systems

– Allow seamless integration of data

• Transaction processing systems (TPS)

– Transaction is a complete event

• Completed in a series of steps

– Tracks and processes transactions

– Each step is monitored

• Details sent to the appropriate person

– Errors must be remedied immediately

• Management information systems (MIS)

– Tools for managers and decision makers

– Organizes and evaluates information

– Summarizes reports based on need

• Managers require different views of data

• Decision support system

– Organizes information for better decisions

– Different data and criteria are evaluated

– Often based on spreadsheet software

– Provides tailored and structured reports

Expert systems

– Perform tasks done by a person

– Analyze data and suggest an action

– Requires a large knowledge base

– Inference engines

• Analyze the data

• Make the decisions

Information Systems Technology

• Intranets

– Private network using internet technology

– Employees use to access data

– Databases are stored on the Intranet

– Access to outside users is blocked

• Extranets

– Outside access to an intranet

– Goal is to simplify a process

– Just-in-time inventory

• Manufacturer keeps little material in stock

• Arranges to have stock delivered daily

• Virtual Private Networks

– Secure connection over the Internet

– Tunneling provides security

• Data transmitted in an encrypted packet

– Employees use to work from home

– Networks use to connect securely

– Once established, the VPN is transparent

• Electronic data interchange (EDI)

– Electronic transfer of data

– Data transferred in a precise manner

– Networks often share an information system

– Over time can save organizations money

• Data warehousing

– Provides 24x7 access to data

– Fault tolerant

– Data security

• Data scrubbing

– Provides for data consistency and validity

– Compares data to a set of rules

• Failures are repaired or removed

– Should be performed at all levels

• Data entry

• Storage

– As rules change data is rescrubbed

Information Systems Hardware

• Server farms

– Collection of servers and mainframes

• Servers work together

– Servers are either distributed or collected

– Uses of server is critical

• Enterprise storage

– Methods and technologies to store data

– Efficiently store large amounts of data

– Data is accessible at all times

– RAID and NAS are two types

• RAID

– Redundant Array of Inexpensive Disks

– Links a number of hard drives

– Provides data redundancy

– Can speed access to data

– RAID 0

• Disk striping

– RAID 1

• Disk mirroring

– RAID 3, 4, and 5

• Disk striping with parity

• NAS

– Network Attached Storage

– Disk storage connected to network media

– Disk system processes and delivers data

– Storage Area Networks (SAN)

• Backup

– Protects files and settings

– Can restore data to an earlier point

– Crucial to any information system

– Transaction rollback

• Logs changes to a file

• Changes are undone when necessary

– Tape backup

• Copies files to a tape

• Files need recopied when necessary

• Nonstop and redundant systems

– Mission critical system

– Must run 24x7

– Most information systems mission critical

– Redundant systems are backup computers

• Backup takes over when necessary

• Scalable and interoperable systems

– Scalability

• Defines a systems ability to grow

• Software and hardware grows

– Interoperable systems

• Work with other systems

• Little configuration is needed

Information Systems Department

• Integral part of any organization

• Maintains equipment, software and data

• Enables other employees to function

• Requires highly trained employees

• Various names

– Information Systems (IS)

– Information Technology (IT)

– Management Information Systems (MIS)