2.5 Manipulation and/or Processing
In this section you must be able to:
• Describe the different modes of operation:
batch, interactive, transaction and realtime, identifying appropriate contexts for
use.
• Describe the characteristics of processing
data in the form of text, pictures, numbers
and sound.
Processing Data
• As a home user of ICT you don’t have a great
amount of processing to do
• A large organisation, however, may have millions of
transactions a day that need processing
• A transaction is an event in the organisation that
needs to be recorded to keep track of its goods and
services. Examples include:
– Ticket sales – they need to be recorded so they are
not over-sold
– Hire companies, libraries, etc. will need to track their
property by recording the loans
– Banking – paying in or withdrawing money
– Recording attendance – e.g. clocking in at factories
or taking the register in classrooms
Transaction Processing
• These transactions are used to update the
state of the business, or the records of people
or items within the business
• For example, if you pay £1000 into the bank,
you would hope that your balance would
increase by £1000
• Some transactions need to be processed
immediately, some can wait until the end of the
day, and some can even wait months
• There are different modes of processing that
can be used to process transactions
Master Files and Transaction Files
• The state of an organisation, or of the customers,
goods or services within an organisation are stored in
master files
• Events occurring within the organisation are recorded
in transaction files
• Many of these transactions will require the master file
to be updated. For example, in a bank, the following
transactions will require the customer’s record to be
updated:
– A change in the customer details – e.g. if they move house
– A customer closing an account
– Someone cashing a cheque written by the customer
– The customer making a deposit
– The customer withdrawing money through an ATM
Modes of Processing
Modes of processing include:
Transaction
Master
• Batch processing
• Real-time processing
• Pseudo real-time processing
Process
You might also hear the terms:
• On-line processing
• Interactive processing
• Transaction processing
Although these are not clearly defined!
Updated
Master
Batch Processing
• Some transactions don’t require an immediate
response - all the transactions can be collected
and processed together; this is called batch
processing
• Payroll systems, for example, only need to pay
people monthly, and all the processing can be
done at once at the end of month.
• Financial institutions might only update
balances at the end of the business day
• Utility companies only need to process meter
readings every month or every quarter to
produce the bills
• Batch processing is usually done on a regular
basis, e.g. daily, weekly, monthly, etc.
Stages in Batch Processing
• Transactions are gathered together in batches
– they may be keyed in from paper records, or
collected electronically from input devices
• Manually entered data will be keyed in off-line,
verified and validated, and stored in a
transaction file
• Transactions may be sorted into the same
order as records in the master file to facilitate
processing
• Processing begins – possibly at a predetermined time, e.g. overnight
• There is no user intervention
• The master file is updated
Interactive Processing
• Not all systems or changes will require a
transaction file to be created
• For example, if you phone up your insurance
company and tell them that you’ve got a new car,
they can update your record while you’re on the
phone
• Systems in which data are entered and processed
straight away are called interactive
• Interactive systems have a dialogue with the user –
e.g. they respond to input and produce an output
• Some systems use a mixture of modes – e.g. you
can ask for your balance from a cash machine (an
interactive process), but if you make a withdrawal
your balance gets updated overnight (a batch
process)
Real-time Processing
• With real-time processing, the system
responds instantly to inputs or events as they
occur
• An example might be a car engine
management system – when you press the
accelerator the engine reacts instantly; it
doesn’t store the information and update the
engine speed overnight!
• Business systems tend to react more slowly –
if you’re booking a plane ticket on-line then a
delay of a few seconds is acceptable; this is
know as pseudo real-time processing
Choosing a Processing Mode
• How do you decide on whether your system
should use batch or real-time processing?
• You need to consider:
– Whether the information from the system needs to
be up-to-date at all times, or whether it’s enough to
be updated at regular intervals
– The scale of the operation – batch processing is
usually used with high volumes of data
– Cost – real-time systems will require faster
communication links and more elaborate backups
and procedures to deal with errors and breakdowns
– Patterns of computer usage – batch processing
often uses spare computer capacity, e.g. by doing
the processing overnight or at weekends when the
computer would otherwise be idle