2.5 Manipulation and/or Processing

In this section you must be able to: • Describe the different modes of operation: batch, interactive, transaction and real time, 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

can be used to process transactions that

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: • Batch processing • Real-time processing • Pseudo real-time processing Transaction You might also hear the terms: • On-line processing • Interactive processing • Transaction processing Although these are not clearly defined!

Process Updated Master 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 pre determined 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