This document defines and provides examples of several types of business information systems: Transaction Processing Systems (TPS) which process business transactions and ensure consistency; Office Automation Systems (OAS) which facilitate electronic office communication; Knowledge Work Systems (KWS) which support knowledge workers; Decision Support Systems (DSS) which help users make better decisions by analyzing data; Executive Support Systems (ESS) which provide executive-level reports; and Group Decision Support Systems (GDSS) which facilitate group collaboration for complex decision making.