Schedule starting point for a task


#1

Hi,
we have a long running business process. We’d like to schedule the starting point of some of the tasks. For example: The process instance starts at 10AM and the first task is started immediatelly. It takes 30min. But the following second task should not start before 11AM. How can we model this in BPMN?
Thanks and best regards, Roland


#2

@Roland configure a Execution listener in the start event and query for running process instances, if the previous processes are still running then throw an exception, so it won’t start the process until the previous completes.


#3

Thank you @ aravindhrs
Unfortunately this is not exactly what we’re looking for, maybe I have to be more precise.
We have one process existing of lets say three tasks exeucted in sequential order
task1(duration: 30min) -> task2(duration 30 min) -> task3(duration 30 min)
In our example we start the process beginnig with task1 at 10AM. If everything works fine the entire process will latest end after 90 minutes at 11.30AM
But in our case we somehow want to schedule task2. For example, we want task2 to be executed “earliest at 11AM”. In this scenario the BPMN engine should wait until one of the following conditions are fullfilled

  • if task1 is ended before 11AM the BPMN engine has to wait until 11AM before it starts task2
  • if task1 is for any reason still running at 11AM, the BPMN engine has to start task2 immediately after task1 is finished

Hope this descibes it a little more precise
Thanks and best regards, Roland


#4

Hi Roland,

how about working with Timer Intermediate Catching Events between the tasks and defining fixed dates for them via variables or expressions? If the timer is over-due, it should fire as soon as you arrive at it.

Hope that helps.

Best,
Tobias


#5

Hi Tobias
thanks for your reply. Nice idea, we’ll give it a try. Will come back here
Thanks and best regards, Roland


#6

Hi Tobias
thank you very much, we tried it out with the proposed timer intermediate event and it works pretty well


Best regards
Roland


#7

Hi Roland,

glad it helped you moving forward! :slight_smile:

Best,
Tobias