BPMN how many pool and lanes should it be in this case study

The case study is about book return system process of a library. the main part is:

  1. customer borrows a book
  2. system will send email to customer after due date
  3. after 7 days not return, librarian will call / email the customer
  4. after 7 days again, a warning msg will be sent to say that case will be escalated to manager
  5. if no return, manager will take over the case
  6. manager will contact staff personnel unit if customer is staff OR contact academic registry department if customer is a student
  7. there are more action after this but it is just about manager trying to close the case, it should not matters for the decision of swimlanes and pools


i have identify the swim lanes and pools to be like this

Customer pool, Academic registry department pool, personnel unit pool, they are all black box

did i get the correct idea for the swimlanes and pool? how can i improve it?
here is the full case study if you need! please help me thank you :slight_smile:
case study.txt (2.7 KB)

Sure, why not post the full case stuff, more information is always useful.

i have uploaded it, please check the attachement in the topic thank you!!

Seems fine to me, the only suggestion i would make is that you could maybe use a better modeler. :wink: