2.5 Manipulation and/or Processing

1. 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.

2. 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

3. 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

4. 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

5. Process Modes of Processing Master Transaction Modes of processing include: • Batch processing • Real-time processing • Pseudo real-time processing You might also hear the terms: • On-line processing • Interactive processing • Transaction processing Although these are not clearly defined! Updated Master

6. 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.

7. 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

8. 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)

9. 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

10. 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