DRAKON diagrams are improved flowcharts.
The DRAKON visual language was originally created to capture software specifications in the aerospace industry. Gradually, DRAKON has gained recognition as a language of requirements for other types of information systems, including web, desktop and mobile applications.
Besides information technology, DRAKON is used in other places where a precise “how to” knowledge is important. Prominent examples are medicine and law.
About the DRAKON language: DRAKON.pdf
ERIL, DRAKON's counterpart for structure diagrams: The ERIL Language