Information Systems & Information Systems & DatabasesDatabases

2.1) Information Systems

• Information systems are created to provide access to information for an organisation or individual.

• They perform a set of information processes involving participants, data/information and information technology.

• In a large number of information systems, the data is held in a database and accessed through a database management system (DBMS).

• The characteristics of an information system are:

•organisation of data into information – careful thought is required to sort and link large amounts of data (e.g. data dictionary)

•analysis of data to give knowledge – analysed data should be output into useful forms, such as tables, charts, queries and forms.

• There are many different types of information systems, including:

•transaction processing systems•decision support systems•expert systems•management information systems

•office automation systems• Transaction processing systems

(TPS’s) deal with the daily transactions of an organisation.

• This could include buying and selling of goods and services, banking, shares and point-of-sale (POS) transactions.

• Organisations rely heavily upon their TPS, a breakdown will disrupt operations, so they must be well designed with solid backup and recovery procedures.

• TPS’s use both real-time and batch processing, depending upon their circumstances.

• Decision support systems (DSS’s) assist people by providing information, models and analysis tools.

• E.g. stockmarket analysis software• A DSS creates a mathematical model

utilising the variables of the situation and then uses various tools to answer ‘what-if’ questions.

• These tools could include statistical tools, databases, spreadsheets and graphics.

• The reliability of the DSS depends upon the accuracy of the model and the manager’s ability to formulate good questions.

• An expert system is a special kind of DSS.

• They are used to provide information and solve problems that would otherwise require a person experienced in that field.

• They are useful in diagnosing, monitoring, selecting, designing, predicting and training.

• An expert system asks a series of questions and compares the answers to a knowledge base.

• A knowledge base is a set of facts and ‘if-then’ rules supplied by an expert or team of experts.

• E.g. online medical diagnosis.

• The answers provided by an expert system are sometimes incorrect, since the logic of the knowledge base is not always followed.

• Management information systems (MIS’s) provide information for the organisation’s managers.

• An MIS provides an overview as to how the organisation is faring.

• E.g. reports on sales, inventory, payroll, orders and budgets.

• Office automation systems provide a means to completing routine administrative tasks.

• They use a range of tools including word processing, databases, spreadsheets, desktop publishing (DTP), presentation programs and project management software.

• They also utilise communications technology such as web browsers, email, instant messaging and telepresence systems.

• Regularly published newsletters and memos are both examples of this kind of system in action.

• Another suitable example is quickly producing large numbers of letters and documents through a mail-merge process.

• Most of these different kinds of information systems use a database.

• Databases are accessed through a software package known as a database management system (DBMS).

• A DBMS has no data in it, but rather accesses and manipulates the data found within a database file.

• A database is an organised collection of data that can be sorted and searched for information.

[Read MovieTime case study (p.39) and then answer Exercise Q.9]