Case Management Model and Notation (CMMN) is a graphical representation for graphically expressing a Case, as well as an interchange format for exchanging Case models among different tools. In this context: "A Case is a proceeding that involves actions taken regarding a subject in a particular situation to achieve a desired outcome" and it is derived from the concept of Case management used e.g. in the legal and medical worlds. CMMN can often require ad-hoc actions.