Information systems are constantly changing and evolving as technology continues to grow. Very importantly the information systems described below are not mutually exclusive and some (especially Expert Systems, Management Information Systems and Executive Information Systems are can be seen as a subset of Decision Support Systems). However these examples are not the only overlaps and the divions of these information systems will change over time. At present there are five main types:
|Transaction Processing Systems (TPS) | |Decision Support Systems (DSS) | |Expert Information Systems (EIS) | |Management Information Systems (MIS | |Office Automation Systems (OAS) |
Types of Information Systems
Information systems differ in their business needs. Also depending upon different levels in organization information systems differ. Three major information systems are 1. Transaction processing systems
2. Management information systems
3. Decision support systems
Figure 1.2 shows relation of information system to the levels of organization. The information needs are different at different organizational levels. Accordingly the information can be categorized as: strategic information, managerial information and operational information. Strategic information is the information needed by top most management for decision making. For example the trends in revenues earned by the organization are required by the top management for setting the policies of the organization. This information is not required by the lower levels in the organization. The information systems that provide these kinds of information are known as Decision Support Systems. [pic]
Figure 1.2 - Relation of information systems to levels of organization The second category of information required by the middle management is known as managerial information. The information required at this level is used for making short term decisions and plans for the organization. Information like sales analysis for the past quarter or yearly production details etc. fall under this category. Management information system (MIS) caters to such information needs of the organization. Due to its capabilities to fulfill the managerial information needs of the organization, Management Information Systems have become a necessity for all big organizations. And due to its vastness, most of the big organizations have separate MIS departments to look into the related issues and proper functioning of the system. The third category of information is relating to the daily or short term information needs of the organization such as attendance records of the employees. This kind of information is required at the operational level for carrying out the day-to-day operational activities. Due to its capabilities to provide information for processing transaction of the organization, the information system is known as Transaction Processing System or Data Processing System. Some examples of information provided by such systems areprocessing of orders, posting of entries in bank, evaluating overdue purchaser orders etc.
Transaction Processing Systems
TPS processes business transaction of the organization. Transaction can be any activity of the organization. Transactions differ from organization to organization. For example, take a railway reservation system. Booking, canceling, etc are all transactions. Any query made to it is a transaction. However, there are some transactions, which are common to almost all organizations. Like employee new employee, maintaining their leave status, maintaining employees accounts, etc. This provides high speed and accurate processing of record keeping of basic operational processes. These include calculation, storage and retrieval. Transaction...