IT

1. INFORMATION SYSTEM
A combination of hardware, software, infrastructure and trained
personnel organized to facilitate planning, control, coordination,
and decision making in an organization. Many organizations work
with large amounts of data. Data are basic values or facts and are
organized in a database. Many people think of data as synonymous
with information; however, information actually consists of data that
has been organized to help answers questions and to solve problems.
An information system is defined as the software that helps organize
and analyze data. So, the purpose of an information system is to
turn raw data into useful information that can be used for decision
making in an organization.
Typical Components of Information Systems
While information systems may differ in how they are used within an
organization, they typically contain the following components:
1. Hardware: Computer-based information systems use computer
hardware, such as processors, monitors, keyboard and printers.
2. Software: These are the programs used to organize, process and
analyze data.
3. Databases: Information systems work with data, organized into
tables and files.
4. Network: different elements need to be connected to each other,
especially if many different people in an organization use the same
information system.
5. Procedures: These describe how specific data are processed and
analyzed in order to get the answers for which the information
system is designed.
The first four components are part of the general information
technology (IT) of an organization. Procedures, the fifth component, are
very specific to the information needed to answer a specific question.

2. Different Types
The many different types of information system can be divided into
categories based on the where they are used in the hierarchy of an
organization.
Management Uses of Information
An IS serves two important functions within an organization. First, the IS mirrors and monitors
actions in the operations process by processing, recording, and reporting business events. For
example, the IS processes customer orders; records sales to customers by updating sales,
accounts receivable, and inventory data; and produces invoices and sales event summaries.
To support managerial activities in the management process, including management decision
making. How do managers use this information? First, they monitor current operations to keep
their ship on course. For example, managers need to know if enough inventory is being produced
each day to meet expected demand. Managers’ second use of information is to help them achieve
satisfactory results for all of their stakeholders (e.g., customers, stockholders). For example,
information can measure attainment of goals regarding product quality, timely deliveries, and
cash flow. Finally, managers use the information system to recognize and adapt in a timely
manner to trends in the organization’s environment. For example, managers need answers to
questions such as: “How does the time it takes us to introduce a new product compare to our
competitors?” “Does our unit cost to manufacture compare to our competitors?” 1 Because
information systems provide critical support to such management activities, one must understand
these activities, including decision making, to understand the features of good information
systems.

3. system documentation
The collectionof documentsthatdescribesthe requirements,capabilities,limitations,design, operation,
and maintenance of asystem,suchas a communications,computing,orinformation processingsystem.
Systems Documentation can cover a very broad range of documents within any industry including IT.
Documentation is especially critical where decisions have been made and should be followed by a
responsible party.
Systems Documentation can cover a very broad range of documents within any industry including IT.
Documentation is especially critical where decisions have been made and should be followed by a
responsible party.
What its Involves
They key to good documentation is that it is clear and concise, so
that anybody other than the author can pick it up and understand
it easily.In many cases, it is more beneficial for a technical
document to be prepared by a group of people. This way you will

4. find that the final output is complete and readable and you can be
sure that everyone is on the same 'sheet of music'.
DATA FLOW DIAGRAM
A data flowdiagram (DFD) isa graphical representationof the "flow"of datathroughan information
system,modellingits process aspects.A DFDis oftenusedasa preliminarysteptocreate anoverviewof
the system,whichcanlaterbe elaborated.[2]
DFDscan alsobe usedforthe visualization of data
processing(structureddesign).
A DFD shows what kind of information will be input to and output from the system, where the
data will come from and go to, and where the data will be stored. It does not show information
about the timing of process or information about whether processes will operate in sequence or
in parallel (which is shown on a flowchart).