Information systems in context
A system is a group of elements that work together to achieve a purpose. The
education system is one example. It is made up of students, teachers, schools,
resources and processes. The education system’s purpose is to provide students
with the basic skills and knowledge necessary to take part in society. Systems can
be large, such as the legal system, or small, such as the system you use to brush
your teeth. A systems may be designed by people, such as the banking system, or
occur in nature, such as the water cycle. In this course we are concerned with
information systems.
An information system performs a set of information processes requiring
participants, data/information and information technology. It performs the
information processes of collecting, organising, analysing, storing/retrieving,
processing, transmitting/receiving and displaying information. Information
systems are created for a purpose and operate in a particular environment.
The relationships between the elements of an information system are shown
in Figure aaa. The links between the elements are represented using two-headed
arrows. This emphasises that the elements influence each other—a change in
one can affect the others. For example, the availability of new technology could
change the information processes, which in turn might affect the type of skills
required by the participants.
Purpose
Information systems have a purpose,
which means they address the needs of a
group or an individual. The system’s
purpose is the reason for its existence and
it is used to measure its success. Information
systems are created to solve a
problem and provide benefits to an
organisation or individual. There are
many different reasons for existence of an
information system.
Individuals may require an information
system whose purpose is:
• to keep track of income and expenses
• to publish a weekly newsletter for a
local athletics club
• to design a multimedia presentation
for the next staff meeting
• to communicate with other people on
the Internet.
Organisations may require an information system whose purpose is:
• to provide stock inventory, sales, payroll, share market, commodity prices or
interest rates information
• to assist decision-making by summarising and comparing data
• to share data and information between individuals and offices in different
locations
• to store and organise information on consumer trends, competition products
or labour costs.
Environment
The environment is everything that influences or is influenced by an information
system and its purpose. It includes any factors that affect the system or are
affected by it. For example, the environment of the local library is not only the
building, but also factors outside the building, such as its location, electrical
power, air-conditioning, communications, and funding from the government.
The environment of a system is constantly changing. Managers of large information
systems need to be aware of new factors that are affecting the system.
One of the main reasons for the environment to change is the progress in
information technology. Twenty years ago, organisations were largely restricted
by geographical boundaries. Today, the environment of many organisations is the
world. The Internet has provided a global marketplace for goods and services.
Organisations can transfer information around the world and move finance
easily between countries. Information technology continues to change at an
extraordinary rate and will continue to affect the environment of information
systems.
Information technology
Information technology is the set of tools used by an information system or its
participants to perform work—it is the hardware and software used by
information systems. It is important to understand that information technology
has no effect unless it is used within an information process. To be effective, the
information technology must be able to support the information process.
Hardware
Hardware is the physical equipment involved in processing information, such as
a computer, network cables and data storage devices. It refers to objects that you
can see and hold. Computers often form the basic hardware of an information
system. Computers are electronic devices that can process data according to
stored sequences of instructions. They have five basic functions: input, processing,
storage, control and output.
• Input involves entering data into the computer. A device designed to assist
the entry of data is called an input device. Input devices include the keyboard,
mouse, scanner, digital camera, video camera and microphone.
• Processing changes data to produce information by following a series of instructions.
Processing is performed by the computer’s central processing unit
(CPU). The CPU is the ‘brain’ of the computer. It takes the data from an input
device, changes it to produce information and sends it to an output
device to be displayed to the user.
Storage involves retaining data over a period of time. Before, during and after
processing, data and programs are held temporarily in memory. To retain data
more permanently, storage devices such as magnetic disks, magnetic tape,
optical disks and flash memory are used.
• Control coordinates the operations of input, processing, output and storage.
The control unit is part of the CPU. The control unit is the ‘organiser’ that directs the flow of data in the computer in the same way as traffic lights
control the flow of cars at an intersection.