START EVENTS | INTERMEDIATE EVENTS | END EVENTS | DESCRIPTION |
 |  |  | A start message arrives from a Participant and triggers the start of a process, or continues the process in the case of an intermediate message event. An end message event denotes a message generated at the end of a process. |
 |  | A Timer cannot be an End Event | A specific time or cycle (e.g. 'every Monday at 9am') can be set to trigger the start of a process, or continue the process in the case of an intermediate timer event. |
 |  | A Rule cannot be an End Event | A start rule event (a.k.a. 'Conditional' Event) triggers the start of a process when the conditions for the rule become true, (e.g. 'Stock prices changes by more than 10% since opening'), or affect the the process in the case of an intermediate rule event. |
 |  |  | A link is a mechanism for connecting the end event of one process to the start event of another process, (Perhaps from one page in a BPD to another). As such I consider that it is not really an 'event' but just an aid to the modeler when modeling large BPDs. The start and intermediate link events 'catch' a link (from another diagram) and the end link 'throws' a link (to another diagram). |
 |  |  | A start multiple event is used when there are multiple ways of riggering a process, or continuaing a process in the case of an intermediate multiple event. Only one of the ways is required to trigger the process. However, for an end multiple event, there are multiple consequences (or results) all of which will occur. (Some drawing tools show a 6-pointed star instead of a pentagon). |