Introduction to Data Processing System

Data processing system
A data processing system is a combination of machines
and people that for a set of inputs produces a defined
set of outputs. The inputs and outputs are interpreted
as data, facts, information, ... depending on the
interpreter's relation to the system.
Types of Data
Mainly Data is divided into two types:
1. Numeric Data
2. Character Data
1. Numeric Data
The data which is represented in the form of numbers is known as Numeric Data. This
includes 0-9 digits, a decimal point (.), +, /, – sign and the letters “E” or “D”.
2. Character Data
Character data falls into two groups.
i. String Data
ii. Graphical Data
String Data
String data consists of the sequence of characters. Characters may be English
alphabets, numbers or space. The space, which separates two words, is also a
character. The string data is further divided into two types.
a. Alphabetic Data
b. Alphanumeric Data
Graphical Data
It is possible that pictures, charts and maps can be treated as data. The scanner is
normally used to enter this type of data. The common use of this data is found in the
National Identity Card.
A collection of data which conveys some meaningful idea is
information. It may provide answers to questions like
who, which, when, why, what, and how.
The raw input is data and it has no significance when it
exists in that form. When data is collated or organized
into something meaningful, it gains significance. This
meaningful organization is information
Observations and recordings are done to obtain data, while
analysis is done to obtain information
Data Processing
Data processing:
Any operation or set of operations performed upon
data, whether or not by automatic means, such as
collection, recording, organization, storage,
adaptation or alteration to convert it into useful
Data Processing Cycle
Once data is collected, it is processed to convert it into useful
information. The data is processed again and again until
the accurate result is achieved. This is called data
processing cycle.
The data processing is very important activity and
involves very careful planning. Usually, data processing
activity involves three basic activities.
1. Input
2. Processing
3. Output
Data Processing Cycle
1. Input
It is the process through which collected data is transformed into a
form that computer can understand. It is very important step because correct
output result totally depends on the input data. In input step, following
activities can be performed.
i) Verification
The collected data is verified to determine whether it is correct as
required. For example, the collected data of all B.Sc. students that appeared in
final examination of the university is verified. If errors occur in collected data,
data is corrected or it is collected again.
ii) Coding
The verified data is coded or converted into machine readable form
so that it can be processed through computer.
iii) Storing
The data is stored on the secondary storage into a file. The stored
data on the storage media will be given to the program as input for
Data Processing Cycle
The term processing denotes the actual data manipulation techniques such as
classifying, sorting, calculating, summarizing, comparing, etc. that
convert data into information.
i) Classification
The data is classified into different groups and subgroups, so that each group or subgroup of data can be handled separately.
ii) Storing
The data is arranged into an order so that it can be accessed very quickly as and when
iii) Calculations
The arithmetic operations are performed on the numeric data to get the required results.
For example, total marks of each student are calculated.
iv) Summarizing
The data is processed to represent it in a summarized form. ft means that the summary of
data is prepared for top management. For example, the summary of the data of student is
prepared to show the percentage of pass and fail student examination etc.
Data Processing Cycle
3. Output
After completing the processing step, output is generated. The main
purpose of data processing is to get the required result. Mostly, the output is
stored on the storage media for later user. In output step, following activities
can be performed.
i) Retrieval
Output stored on the storage media can be retrieved at any time. For
example, result of students is prepared and stored on the disk. This result can
be retrieved when required for different purposes.
ii) Conversion
The generated output can be converted into different forms. For
example, it can be represented into graphical form.
iii) Communication
The generated output is sent to different places. For example,
weather forecast is prepared and. sent to different agencies and newspapers
etc. where it is required.
Types of data processing
 Scientific data processing
 Scientific data processing "usually involves a great deal of
computation (arithmetic and comparison operations) upon a relatively
small amount of input data, resulting in a small volume of output."
 Commercial data processing
 Commercial data processing "involves a large volume of input data,
relatively few computational operations, and a large volume of
output." Accounting programs are the prototypical examples of data
processing applications.
 Data analysis
 "Data analysis is a body of methods that help to describe facts, detect
patterns, develop explanations, and test hypotheses." For example,
data analysis might be used to look at sales and customer data to
"identify connections between products to allow for cross selling
Computer Processing Operations
A computer can perform only the following four
operations which enable computers to carry out the
various data processing activities we have just
(a) Input/Output operations
A computer can accept data (input) from and
supply processed data (output) to a wide range of
input/output devices. These devices such as
keyboards, display screens, and printers make
human-machine communication possible.
Computer Processing Operations
(b) Calculation and text manipulation Operations
Computer circuits perform calculations on
numbers. They are also capable of manipulating
numerics and other symbols used in text with equal
Computer Processing Operations
(c) Logic/Comparison Operations
A computer also possesses the ability to perform
logical operations.
For example, if we compare two items represented by
the symbols A and B, there are only three possible
A is less than B (A<B); A is equal to B (A=B): or A is
greater than B
A computer can perform such comparisons and the,
depending on the result, follow a predetermined path to
complete its work. This ability to compare is an
important property of computers.
Computer Processing Operations
(d) Storage and Retrieval Operations
Both data and program instructions are stored
internally in a computer.
Once they are stored in the internal memory,
they can be called up quickly
or retrieved, for further use.
Simple example
A very simple example of a data processing system is the process
of maintaining a check register. Transactions— checks and
deposits— are recorded as they occur and the transactions are
summarized to determine a current balance. Monthly the data
recorded in the register is reconciled with a hopefully identical list
of transactions processed by the bank.
A more sophisticated record keeping system might further identify
the transactions— for example deposits by source or checks by
type, such as charitable contributions. This information might be
used to obtain information like the total of all contributions for the
The important thing about this example is that it is a system, in
which, all transactions are recorded consistently, and the same
method of bank reconciliation is used each time.
Flowchart of process
 Select application domain (AD)
 Identifying the business environment
 Developing the business charts (two types)
 Developing the static model:
 Extracting the sets of objects and relations and
representation in the forms of communication
diagrams/ flow charts
 Designing the dialogue structures in the form of
oriented graph models for 2 ÷3 user classes.
Report structure
Brief description of application domain
Developing the business charts
Developing the communication diagrams and interface
 Designing the dialogue structures for several user classes
 Resume
 Bibliography
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