There are four main types of information systems in existence within firms. These systems serve operations, middle and senior administration levels. The operational level management mainly uses transaction processing systems such as order processing and hotel room reservation that monitor the flow of routine processes required to carry out business. Both management information systems and decision support systems generate reports and offer access to the firm up to date performance and past records.
Management information systems acquire information from transaction processing systems and are not analytical.
Decision support systems support the decision-making process, especially when the decisions are distinctive and volatile. They are more analytical than management information systems. Decision support systems obtain data from both external and internal sources.
Executive support systems offer highly classified information to the senior managers for decision-making. These are always in the form of charts and graphs and possess limited analytical ability.