This International Standard specifies the set of definitions, conventions and activities of the COSMIC Functional Size Measurement Method. It is applicable to software from the following functional domains: a) application software; EXAMPLE Banking, insurance, accounting, personnel, purchasing, distribution or manufacturing. b) real-time software; EXAMPLE Software for telephone exchanges and message switching, software embedded in devices to control machines such as domestic appliances, lifts and car engines, for process control and automatic data acquisition, and within the operating system of computers. c) hybrids of the above. EXAMPLE Real-time reservation systems for airlines or hotels. This International Standard has not been designed for measuring the functional size of a piece of software, or its parts, which — is characterized by complex mathematical algorithms or other specialized and complex rules, such as can be found in expert systems, simulation software, self-learning software and weather forecasting systems, or — processes continuous variables such as audio sounds or video images, such as can be found in computer game software, musical instruments and the like.