An information system is an integration of many data sets that ensure successful completion of a business objective. They help keep data organized and perform analysis, usually converting raw data into useful information for decision making.

Information systems are not standalone, rather they integrate people (users), business processes, and Information Technology (hardware and software) to help people complete their tasks.

Historically, information systems are used mostly by employees inside business organizations rather than independent individuals, because businesses operate processes at a much larger scale that demands computer assistance despite its cost. However, that is changing rapidly.

People make decisions on three levels: operational, management, and strategic. Because information systems are built to serve the needs of people, all six kinds of information systems fall into those three categories.

1. Transaction Processing Systems (operational)

2. Office Automation Systems (operational)

3. Knowledge Management Systems (operational)

4. Management Information Systems (management)

5. Decision Support Systems (strategic)

6. Executive Support Systems (strategic)

1. Transaction Processing Systems

• Billing, banking, hiring, inventory, customer relationship management, payroll, shipping

• Control and management of a service or routine activities

• Reliable, accurate, transactional, safe, secure, accessible to users

• Structured data

2. Office Automation Systems

• Printing, mailing, calendar, email, directory, reports

• Streamline clerical and managerial daily tasks

• Optimize communication, improve collaboration across departments

• Network of tools, technologies and people

3. Knowledge Management Systems

• Employee training materials, company policies and procedures, FAQs, sales database, competitor database

• Provide access to external information needed by workers who need outside knowledge to complete their roles, i.e. access to competitor data to help sales optimize pitching a customer

• Ensures technical capabilities are consistently integrated across the org

4. Management Information Systems

• furnish reports and data in aggregate form to help management monitor performance, optimize decision making related to organization’s core functions (meet targets and oversee business units)

• Sales summaries, performance data, historical records

• integrated with the org's transactional systems

• semi-structured data

5. Decision Support Systems

• Process information to help managers make the right decisions at the right time, create and gather evidence

• i.e. a bank manager will assess evolving loan trends to determine which yearly loan targets to meet

• Can analyze information that is rapidly changing and cannot easily be determined in advance

• Automated, human operated, or both

• Unstructured data

6. Executive Support Systems

• Senior decision making; like DSS but graphical representation of a broad view

• track internal performance, monitor competitors, pinpoint growth opportunities, see internal compliance issues

• Unstructured data