The next step in our BPMN lecture series is “events.”

“Events” are steps in a workflow that are not tasks (work) or splits (business rule). This definition probably ruined your intention of reading the rest of the article, so let’s try some different definitions.

Here are some representative events:

  • A human is going to start the process (Normal Start Event)
  • The clock is going to start the process (Timer Start Event)
  • We’ll start once we get a letter (Message Start Event)

And some more:

  • We’re going to send a letter (Throwing Message Intermediate Event)
  • We’re ending here (Normal End Event)
  • Everything is finished here, even if there are some incomplete stuff (Terminate End Event)
There are over 60 registered events in the standard BPMN 2.0, but only a few are usually used in BPM systems. Some people may want to utilize all sorts of available events, but that probably won’t be the best thing for those trying to read and understand the workflow diagram. The best thing about BPMN is that many people can intuitively understand it, so we’re going to be strict and say the above six events are adequate for everyday use.

 

BPMN Sample: Message Throwing



The above workflow sample uses the fourth event, “We’re going to send a letter (Throwing Message Intermediate Event).” There is only one task, which might be called the “Write an email task.” Of course, there are two other events in the workflow (Normal Start Event and Normal End Event). This is not meant to be a practical workflow sample, but it may come in handy when Gmail and Facebook and Yahoo! are all down, but for some reason only your BPMS is alive. (??)

 

BPMN Sample: Message Throwing Never-Ending

Now, in the below workflow the flow always loops back to the first task. In other words, every time the user write an email, the Throwing Message Intermediate Event is sent, and so forth. (It never ends.)
This may be useful if you’re the type of person to keep sending the same template email to your boss and team members. (But, just to let you know, it’s not to be used for sending repeated love letters to someone.)