The natures and scopes of information required managers and different levels in an organization vary considerably. Organization required different types of information system to meet their needs. The fields of information system have come a long way in last few decades. An increasing no of managerial personnel rely on computers and information systems to make decisions. Managers at different levels in an organization make different kind of decision (Operational, tactical and strategic). So, that the types of information necessary to support their decision are also different. Accordingly different types of information systems are designed to meet various information needs of managers.
There are four types of information systems exist:
1. Transaction processing system(TPS)
2. Management information system(MIS)
3. Intelligent support systems(ISS) consisting of decisions support systems (DSS), executive information systems(EIS)and expert systems(ES)
4. Office automation system(OAS)
2.2. TRANSACTION PROCESSING SYSTEM
The main purpose of transition processing system is to records, process validates & store transition death takes place in various function area of a business for future retrieval of use.
• Transaction can be internal or external. When a department order office supplies from the purchasing department an internal transaction occurs.
• When a customer places an order for a product an external transition occurs.
• This processing system is various used in this organization such as finance accounting, manufacturing, production human resources, marketing, Engineer quality control and resource and development.
Steps in Processing a Transaction
Data must be processed to become use full information .There are following 6 steps in processing a transaction.
1. Data entry
2. Data validation
3. Processing & revalidation
5. Output generation
6. Query support
Data entry: Transaction data must first be enter in to the system .A number of input devices exist for entering data including the key board & the mouse. The document generated at the source where the transaction occurs are called source document & becomes input data for the system.
Example: when a customer returns an item at a stored the sales receipt becomes the source document for the transaction return item for returned for replacement.
Data validation is essential in transaction processing. It ensures the accuracy & reliability of data comparing actual data with predetermine standard or known results.
There are 2 steps in validation.
(2) Error correction.
Error detection- Checking the data for appropriate format, checking for missing data, invalid data & inconsistence data.
Error correction- Error correction procedures are design to ensure that all have been corrected & that no errors have been introduced during the process. The technique used for correcting the error depends on the type of errors and the nature of the application.
Data Processing and revaluation:
After the validation of accuracy & reliability of data, the data are processed in following 2 modes
Online transition processing.
Online transition processing:
Online means that the data input device directly linked to the TPS. The data are directly process as soon as it is entered to the system. In this system the information is always no time lag between data creation &data processing. Ex- ATM
Batch processing :
In batch processing, transactions are accumulated over time & Processed periodically.
Processing may be done in a daily, weekly, monthly basis or any other time period appropriate to the given application.
e.g.-an organisation may process its sale proceeds on daily basis at the end of each day, and its daily expenses on a monthly basis.
Data storage is another important function because the values of usefulness of data diminish if data are not properly stored.
E.g. magnetic tap is obtain use to store data i.e. batch processed. However, online transaction. Processing release on other type of storage media, such as magnetic disk. It is to be noted that storage in output not always occurs in the same order. One can output the result of the transaction to the decision maker and then store them, or store the result and then output then to the decision maker.
The output can be communicated to the decision maker, after the data are input, validated, processed, revalidated, & stored, in the following 2 ways:
• Documents and reports
• Forms (screens and panels)
Documents are popular output method. Some Examples: Invoices, pay checks, purchase invoices, sales receipts & job orders.
A document is usually a record of one transaction, where as a report is a summary of two or more transactions. Nevertheless, these terms are obtained interchangeable.
Computer o/p can also appear or computer screens & panels. Such soft-copy presentations are known as forms.
Query support. (asking questions)
It is facilities allow users to access data and information that may otherwise not be readily available.