Between pools event messages.

The process starts in pool 1 and sends a manual email to pool 2 (that's when the process starts in pool 2), should I use "message start" or "message event" as the received message in pool 2?

Comments (4)


Dear Neymar,

More than one pool in a diagram represents interaction between separated business entities or performers.

Many business processes require interaction between each other to be correctly performed and accomplished. In BPMN these interactions are defined as a sequence of activities that represent message exchange patterns between the entities involved. In BPMN this behavior is know as Collaboration.

The following article explains how to create a collaboration between two o more pools according your business needs:

Best Regards


Thanks Juan, very helpful! It confirms that I should use "message start event" when the other pool depends on a communication in order to start a process, and I shouldn't use "intermediate message event" to start or end the pool process.



I have tried to throw and catch a message to another pool and I can't make it work. The message is just not flowing properly.

Can I get some suggestions about what I might be doing wrong? Please see attached image.



Dear Lucas,

The BPMN standard states that messaging between pools has to be with a dashed line instead of a continous line (see images attached).

This is usually done by creating the event that throws the message and the event that receives it, and then selecting the dashed arrow to connect them. If it can't be done directly, then connect the dashed arrow to the pools, and then move the ends of the arrow until they connect to their respective event.

Please try and see if this helps you with your question. If not, we would suggest you create a new question since comments done to posts this old tend to get lost.

All the best,

Laura G