computer processing techniques

7/29/2019 Computer Processing Techniques

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Computer Processing Techniques

UNIT 1


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DATA V/s INFORMATION

DATA INFORMATION

Raw facts or figures Finished one

Unstructured Structured

Unprocessed data Processed data

What exists What is required


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Data Processing

It is the conversion of data into more useful form i.e.transmission of data into meaningful information.

Simplified Version

INPUTData

PROCESSING

OUTPUTInformation

Detailed Version

DATARecord,

checked

andprepared

InputPROCESSIN

GBy computer

MAINTAINED DATAe.g. permanent

details of employees

Informatione.g. Pay slips


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Kinds of data processing

1. Manual data processing abacus, slide rule, Napier

bones

2. Mechanical data processing

Electromechanicaldevices such as calculators, tabulators.

3. Electronic data processing Using systems

Objectives of data processing

Handle data

Qualitative and quantitative data

Appropriate and timely information Helps in decision making

Improving productivity


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Steps Of Data Processing

1. Preparation of source documents

2. Input of data

3. Manipulation of data (shifting, sorting and rearranging

the given input)

4. Output of information

5. Storage of information


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DATA BASE

It is the huge reservoir of data.

Data base is an organized collection of files of

information that has been systematically recorded

and may form the basis of a computer memory and

designed for easy access by authorized users.

Database Management System (DBMS)

It is a system for operating the data base

The system or set of rules and methods allows for

the definition, creation, updation, reading,

maintenance and protection of the data base.


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Methods /Modes Of Data Processing

1. Single User System

2. Batch Processing

3. Multi-Programming

4. On-Line Processing

5. Real Time Processing

6. Time Sharing

7. Distributed Processing

8. Multi-Processing


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1. Single User System

It indicative of one of the earlier stages of

computer development.

Here only one person can work at a time.

If the system is meant for the use of many

persons, much time is wasted waiting for one

person to finish his program

COMPUTER 1

USER 1 USER 2

COMPUTER 2


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2. Batch Processing

It is an old system but it is still for processing in

which the capacity of the C.P.U is limited.

Here the data is collected and accumulated into

batches and processed periodically

Here emphasis is on maximizing the computer

resource utilization.

Jobs are processed one after the other without

any user interaction.


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e.g. Telephone billing: Here the subscriber does not

get bill for every call he makes. Instead, his calls are

recorded at a centralized place and are processed on

a predetermined period of time to prepare his bills.

Drawbacks

Time gap between capture of data

Time consuming

Delay in generating reports

Stores Dept

Transaction

Data preparation

Punch cards

COMPUTER

REPORTS


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3. Multi-programming / Multi tasking

In batch processing the memory and ALU are not

fully utilized.

Multi-programming enables to store execute more

than one program in the C.P.U at the same time.

When I/O devices are performing certain tasks the

C.P.U may not be doing any task, it may be lying

idle so it is desirable to process a number of

programs concurrently. This is achieved by

overlapping the C.P.U & I/O operations when several

programs are running simultaneously.

Improvement over batch processing. It does not

allow users to interact with the computers


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INPUT OUTPUTPROGRAM 1

PROGRAM 2

PROGRAM 3

Processing


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4. Multi-Processing

Multiprocessing systems have 2 or more CPU which

have the ability to execute two or more jobssimultaneously.

Instructions from several programs are carried out by

different CPUs at the same time.

When one CPU fails then the other takes over the

processing

In some other, networks are formed by interconnecting

the CPUs , the small CPU called front end processors

are used for I/O operations, scheduling, controlling of

jobs. In some each CPU perform only specific type of

Ad


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Advantages

More efficient use of hardware resource other than

cpu.

High reliability is ensured by the provision of automatic

take over of complete work by other CPU in case of

break down

Disadvantages

Large memory is required as it require many data and

programs in memory at any time

Very expensive as it incur high operation and

maintenance cost

It requires highly sophisticated operating system


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5. On-Line Processing

Here data is not accumulated, instead data it is

entered and executed directly. Data is transmitted between I/O devices and a

computer system via communication links.

Here many users have direct access to the same

system and the file updated as soon as the

transaction is completed

The online system consist of a large computer

connected to many online terminals which

communicate with it.


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Here the system interacts directly with the user.

Records are updated at any time whereas in batch

processing updating may be once in a week.

E.g.

Banking : It is possible to inform bank customers of

the status of their accounts in response to an enquiry by

accessing relevant file using online terminal.

Benefits

Reduction in paper work

Improved accuracy

File updating

Easy access to file

Improved customer service

6 R l Ti P i


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6. Real Time Processing

Also called Interactive mode or direct mode

It is called a real system because it has to give

results based on dead lines which are imposed.

User can have direct contact with the computer

through his terminal.

Data is processed on the spot and no delay

between the time data is available and the time it

is processed.

It is the technique of updating files, transactions,

data immediately after the event to which it

occurs.


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Suitable for business operations such as

Wholesale supplier & manufacturer Airline seat availability

Manufacturing

Terminal1

Terminal4

Terminal3

Terminal2

Computer

Data

7 Ti Sh i / M lti t


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7. Time Sharing / Multiuser system

It allow each user to interact with the computer.

Individual user has an independent terminal

connected to the main computer which does all the

processing work.

The processor time is shared between two or more

persons

The processor switches from one users job to

another at a rapid rate under the control of a

monitor program.

This concept is time based. All the users have the

same priority so they get equal amount of


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User 1

User 2

User 3

User 4

HOST COMPUTERTIME 1 USER 1TIME 2 USER2TIME 3 USER3TIME4 USER4

TIME5 USER1TIME 6 USER2

8 Di ib d P i


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8 .Distributed Processing

It is a network of several computers in remote stations, each

of which is linked to a single host of computer. Processing

power is distributed among several locations

Larger computer central computer maintains the firms

master data base.

Each system is fully independent computer that maintains its

own local data base in addition to communication with the

master computer. All these systems are tied together to a

high speed communication network

E.g. In the retail industry, each stores network does its own

processing but is under the centralized control of the stores

head quarters


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Advantages

Accessing unused processing power

Distance and location is not a barrier

The system is more responsive to the local needs

Resources can be shared

Computer power can be added or removed according

to the needs

Disadvantages

Dependence on communication technology

Incompatibility between equipments


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Transaction Processing

A transaction is an update made to information in a

database

In electronic data processing data is processed in the

computers automatically. Transactions are carried out

automatically through computers and its known as

Transaction processing systems. These systems

supports day to day operations.

Payroll, inventory are some of the transaction

processing systems


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Types Of Transaction Processing System

Online Transaction Processing

This is the direct communication method between the

operator and the transaction program. It will provide

immediate results. Here transactions are processed to

update a file or to make modifications in a file after the

transactions occur.

Batch Transaction Processing

Transactions are grouped together & processed

periodically on a sequential basis.

computer processing techniques

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