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.

Introduction to 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.

Data processing system

Mainly Data is divided into two types:

1. Numeric Data2. Character Data

1. Numeric DataThe 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 DataCharacter data falls into two groups.

i. String Dataii. Graphical Data

String DataString 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 Datab. Alphanumeric Data

Graphical DataIt 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.

Types of Data

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.

or

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

or

Observations and recordings are done to obtain data, while analysis is done to obtain information

Information

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 information.

Data Processing

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) VerificationThe 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) CodingThe verified data is coded or converted into machine readable form so

that it can be processed through computer.

iii) StoringThe 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 processing.

Data Processing CycleStep-1

2.Processing The term processing denotes the actual data manipulation techniques such as classifying, sorting, calculating, summarizing, comparing, etc. thatconvert data into information.

i) ClassificationThe data is classified into different groups and subgroups, so that each group or sub-group of data can be handled separately.

ii) StoringThe data is arranged into an order so that it can be accessed very quickly as and when required.

iii) CalculationsThe arithmetic operations are performed on the numeric data to get the required results. For example, total marks of each student are calculated.

iv) SummarizingThe 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 CycleStep-2

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) RetrievalOutput 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) ConversionThe generated output can be converted into different forms. For

example, it can be represented into graphical form.

iii) CommunicationThe 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.

Data Processing CycleStep-3

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 campaigns."

Types of data processing systems

A computer can perform only the following

four operations which enable computers to carry out the various data processing activities we have just discussed.(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 efficiency.

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 outcomes.A is less than B (A<B); A is equal to B (A=B): or A is greater than B(A>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 quicklyor retrieved, for further use.

Computer Processing Operations

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 year.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.

Simple example

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.

Tasks

Annotation Contents Task Brief description of application domain Developing the business charts Developing the communication diagrams and

interface tables Designing the dialogue structures for several user

classes Resume Bibliography

Report structure