Ch 26

Objectives

You should understand the differences between batch processing, online processing and real-time processing, including: Billing systems Booking systems Payment systems Real-time systems

Types of processing

There are three basic types of processing: Batch processing Online processing

▪ This is sometimes known as transaction processing

Real time process control

Batch processing

1. With Batch Processing, a number of jobs are collected together over a period of time

2. They are loaded onto a computer system (in a job queue)

3. And then processed all at once (in a batch)

Once the batch processing starts, there is no need for any human intervention at all

It can only be done where there are no timing constraints (ie no response is needed from the computer right away)

Batch Processing

Examples of batch processing are:

the processing of bank cheques

payroll non-automatic stock

control systems utility billing

Batch Processing : Advantages

Can be performed at night when the computer system is not so busy

People do not need to be involved

Batch Processing : Disadvantages

Data is only up to date only when the batch processing has finished

Cannot produce adhoc reports

Online processing

Data is entered by the user, and the computer processes the data straight away.

Processing done as quickly as possible; booking of airline ticket or cinema ticket (these need to be marked as “sold” or “unavailable” immediately the booking is confirmed).

Sometimes called interactive processing

File is updated as each transaction is processed eg ATM, flight booking etc

Online Processing : advantages and disadvantages

Type of processing

Advantages Disadvantages

Online/ Interactive Processing

Immediate processing, up to date data

Files held online, can do ad hoc reports

Audit trails hard to perform

Very little paperwork, so harder to check for errors, etc

Examples of Online processing

Flight bookingsCinema bookingsTheatre bookingsATM withdrawals

How an online booking system works

Online booking systems rely on the ability to update files immediately, in order to prevent double-booking of seats etc

There are a number of steps involved: the order of these is important

Online booking: steps 1

Customer logs on to theatre website and clicks on required performance

Enter date & time + number of seatsSeating display: choose seats If seats are available, seat numbers

and price are displayedCustomer clicks ‘confirm’Seats are now set temporarily in the

theatre database as ‘unavailable’

Online booking: steps 2

Customer enters personal details (eg username & password

Select payment method & make payment

EFTPOS system contacts customer’s bank and enquires if funds are available

Payment is confirmedReference number onscreen/emailDatabase updated with the

transaction

Real time Process Control

The computer responds instantly to events occurring. E.g. Flight simulator

Usually involves sensors and feedback loops

Real time mode is used in computers that have to react very quickly to inputs requiring immediate outputs (e.g. aircraft ‘fly-by-wire’ controls).

Real time Process Control (advantages and disadvantages)

Type of processing

Advantages Disadvantages

Real Time Processing

Reaction to input

Input can be from sensors – automatic feedback loop possible

Can be done by an embedded microchip in small home appliances

Expensive to develop

Very fast processor required

Real Time Processing

Examples of real-time processing are any control system which uses sensors requiring immediate response e.g.

Rockets fired onto space Robots Computer controlled air

conditioning / Central heating / burglar

alarm Computer controlled

greenhouses etc.

Examples of processing types

Energy / Electric company

Theatre Air line

Batch Processing

Printing electric bills

Setting up seating plan for new play

Setting flight schedules

Online Processing

Bill enquiry system

Seat enquiry system

Flight enquiry system

Real time Process Control

Power plant temperature management

Air conditioning

Autopilot

Criteria for choosing processing methods

Things to consider when choosing a processing method:

1. Whether information needs to be up to date at all times

2. Scale of the operation: Batch systems suited to processing of huge amounts of data

3. Cost: Real time system more expensive; more complex backup and recovery procedures required

4. Computer usage: Adv of batch, can process overnight on mainframe computers