sequenceDiagram
participant System
participant External Actor 1
participant External Actor 2
System->>External Actor 1: Interaction 1
External Actor 1->>System: Response 1
System->>External Actor 2: Interaction 2
External Actor 2->>System: Response 2
In general: A description of a potential sequence of events that lead to a desired (or unwanted) result.
In RE: An ordered sequence of interactions between partners, in particular between a System and external Actors. May be a concrete sequence (instance scenario) or a set of potential sequences (type scenario, Use Case).
