Information Systems: Definitions and Components
What Is an Information System?
From a functional perspective; an information system is implemented medium for the
purpose of recording, storing, and disseminating linguistic expressions as well as for the
supporting of inference making. From a structural perspective; an information system
consists of a collection of people, processes, data, models, technology and formalized
language, forming a cohesive structure.
The functional definition focuses on what actual users -do with the information system
while using it. They communicate with experts to solve a particular problem. The IS are
socio-technical systems, i.e., systems consisting of humans, behavior rules, and
conceptual and technical artifacts.
An information system can be defined technically as a set of interrelated components
that collect, process, store, and distribute information to support decision making and
control in an organization. The purpose of information systems is supporting decision
making, coordination, and control, they may also help managers and workers analyze
problems and create new products.
Three activities in an information system produce the information. These activities are
input, processing, and output. Input captures or collects raw data from within the
organization or from its external environment. Processing converts this raw input into a
more meaningful form. Output transfers the processed information to the people who
will use it.
Information systems also require feedback, which is output that is returned to appropriate
members of the organization to help them evaluate or correct the input stage.
Components of Information Systems
1. Resources of people: (end users and IS specialists, system analyst, programmers, data
administrators etc.).
2. Hardware: (Physical computer equipment and associate device, machines and media).
3. Software: (programs and procedures).
4. Data: (data and knowledge bases).
5. Networks: (communications media and network support).
People Resources
• End users: (also called users or clients) are people who use an information system or
the information it produces. They can be accountants, salespersons, engineers, clerks,
customers, or managers.
• IS Specialists: people who actually develop and operate information systems. They
include systems analysts, programmers, testers, computer operators, and other
managerial, technical, and clerical IS personnel.
Briefly, systems analysts design information systems based on the information
requirements of end uses, programmers prepare computer programs based on the
specifications of systems analysts, and computer operators operate large computer
systems.
Hardware Resources
• Machines: as computers and other equipment along with all data media, objects on
which data is recorded and saved.
• Computer systems: consist of variety of interconnected peripheral devices. Examples
are microcomputer systems, midrange computer systems, and large computer systems.
Software Resources
Software Resources includes all sets of information processing instructions.
• System software, such as an operating system
• Application software, which are programs that direct processing for a particular use of
computers by end users.
• Procedures, which are operating instructions for the people, who will use an
information system. Examples are instructions for filling out a paper form.
Data Resources
Data resources include data (which is raw material of information systems) and database.
Data can take many forms, including traditional alphanumeric data, composed of
numbers and alphabetical and other characters that describe business transactions and
other events and entities. Text data, consisting of sentences and paragraphs used in
written communications; image data, such as graphic shapes and figures; and audio
data, the human voice and other sounds, are also important forms of data.
Data resources must meet the following criteria:
• Comprehensiveness: means that all the data about the subject are actually present in
the database.
• Non-redundancy: means that each individual piece of data exists only once in the
database.
• Appropriate structure: means that the data are stored in such a way as to minimize the
cost of expected processing and storage.
Network Resources
Telecommunications networks like the Internet, intranets, and extranets have become
essential to the successful operations of all types of organizations and their computer-
based information systems. Telecommunications networks consist of computers,
communications processors, and other devices interconnected by communications media
and controlled by communications software. The concept of Network Resources
emphasizes that communications networks are a fundamental resource component of all
information systems.
Network resources include:
• Communications media: such as twisted pair wire, coaxial cable, fiber-optic cable,
microwave systems, and communication satellite systems.
• Network support: This generic category includes all of the people, hardware, software,
and data resources that directly support the operation and use of a communications
network. Examples include communications control software such as network operating
systems and Internet packages.
Some types of networks:
1 – Wide Area Network [ WAN ] 2 – Local Area Network [ LAN ]
3 – Personal Area Network [ PAN ] 4 – Wireless Networks. [Wi Fi – 3G 4G ]
