1. Batch Processing.
Batch processing is a technique in which data to be processed or programs to be executed are collected into groups to permit convenient, efficient, and serial processing. It is the simplest form of data processing. With this method, data is entered to the information flow in large volumes, or batches. That is, the processing by computer is performed periodically, at specified time intervals (weekly, monthly, etc) when large volumes are accumulated. Daily transactions in a business establishment, for example, may be batch processed on a weekly basis. Instead of being processed periodically when a sufficient volume has been accumulated.
Advantages of batch processing are:
- Economical when a large volume of data must be processed and
- The most appropriate method for those applications (e.g., payroll) where the delay caused by accumulating data into batches does not reduce the value of the information.
Limitations of batch processing are:
- It requires sorting prior to processing
- Reduce timeliness in some instances and
- Requires sequential file organization.
2. On-line Processing.
The term “on line” refers to equipment or devices under the direct control of the central processing unit (CPU) of a computer. An on-line operation, then, is one which uses devices directly connected to the CPU either for data entry or inquiry purposes. That is, with a terminal we can either enter data or inquire about the status of some record or file that is stored by the computer.
3. Real-time Processing.
Real- time processing is a method of data processing which has the capability of a fast-response to obtain data from an activity or a physical process, perform computations, and return a response rapidly enough to affect the outcome of the activity or process. In order words, the processing of data is done immediately.
Airline reservation systems, for example, require immediate processing. Each time a ticket is issued or cancelled, or a plane’s schedule is altered, the data must be immediately entered sing is also used in keeping track of the availability of motel and hotel rooms, and in immediate updating of customer records in saving banks.
4. Distributed Processing. The most complex level of computer processing, distributed processing, generally consists of remote terminals linked to a large central computer system to help the user conduct inquiries about accounts, process jobs, or other data processing operations. Distributed computer-communications network is similar in some respects to public utilities such as telephone and electric companies – e.g., electric power plants are geographically dispersed and the energy resources generated are transmitted through a coordinating regional network or grid to the places where the energy resources are needed.
Some of the advantages of distributed processing system are:
- central processor idle time is reduced.
- sophisticated computers and a growing library of applications programs may be immediately available to end-users whenever needed.
- skilled professionals are available to help users develop their own specialized applications.
- managers may be able to react more rapidly to new developments and interact with the system in order to seek solutions to unusual problems.
The possible disadvantages are:
- the reliability and the cost of data communication facilities used, and the cost and quality of the computing service received, may be disappointing in some cases.
- input/output terminals are often rather slow and inefficient.
- provisions for protecting the confidentially and integrity of user programs and data files are generally ineffective against a skilled penetrator.