OCR A2 ICT G063 - Chapter 2

a) Batch, Interactive and Real-time Systems

Batch Processing

The data will be saved and processed over a period of time, delayed response time, carried out when the system is less busy such as at night, minimum user interaction required, less disruption to the work schedule, enables peripherals to be accessible in the day when they are most needed, code-based user interface

Examples – calculating wages of the staff at the end of each month, mail shot to customers, invoices prepared at the end of the day, calculating products to order, online competition, bills, monthly bank statements

Employees’ salaries – information is prepared before processing, no human interaction, run when the processing load is at a minimum, be scheduled at the same time every month, same process applied every time it is run

Interactive Processing

This waits for a response from the end user, can be paused as long as it is completed within the given time frame, used to book airline tickets, graphical user interface

Examples – booking tickets, ordering online, booking a holiday, handling bank accounts

Prevention of double booking theatre seats – seat requested is locked whilst the order is processed, booking is completed or the seat is released

Real-time Processing

The processing takes place at once, the database is affected instantly, needed when the customers are in the store and the system is very busy, waits for an automated response from the system, needs to be within the given time period, show location of aircraft at that moment, user interface based on users requirements

Examples – automated stock control, traffic lights, heart rate monitor, computer games

Check-in systems – data is processed at the time required, response time by the system is critical, delays in processing would be unacceptable and cause long queues, large numbers of passengers have to go through check-in within a given time slot, allow several employee transactions to take place simultaneously, responds immediately to the data entered by the employee

b) Types of Operating Systems

Single-user

Can only be used by one person at a given time, different folders for different users, likely to be multi-tasking but for a single-user, can be a single application OS,

Single application – runs one application at a time for one user e.g. iPod shuffle, TV, phone

Multi-tasking – a single user has many applications running with generally more memory to allow it to run many applications at once e.g. laptop

Multi-user

More than one user can access the system at a time, a standard computer running a single user multi-tasking operating system that is connected to a network e.g. a school network

Multi-tasking – each user can use more than one application at a time

Multi-tasking

Characteristics – processor carries out more than one process at the same time, more than one CPU, OS gives specified time to applications, OS waits for the program to give back control (co-operative multi-tasking)

Interactive processing

User interaction with the OS whilst one or more programs are running, there…