There may be occasions when control needs to be exercised over what action a user performs and the response of System Architect to those actions. This may be to prohibit certain operations, provide warnings, and enforce behavior or to perform additional operations. On those occasions it is necessary to identify the action explicitly at the time of its occurrence and to respond accordingly.

Actions that occur at a given point of time are referred to as Events and these can be handled in System Architect as and when they occur.

System Architect recognizes a number of events such as when a symbol is placed on a diagram, a diagram is saved, or an encyclopedia is opened.