How to model a process where portions of it are repeated

[darylo]

Hi,
I am looking at BPMN for the first time and in an attempt to model a
process we use I have encountered a problem. All processes that I have
seen in examples have been nice and clean A->B->C->D->E type processes
with branches and conditions but basically all have unidirectional
paths through each task from A to E. but the one that I have while not
complicated involves the ability for some SubProcesses to be repeated
throughout the process so A->B->C->D->B->E for example. I cannot see
how I can model this in BPMN. It seems a simple thing to want to do to
reuse the subProcess but I cannot see how to introduce it without
creating ambiguity.
I assume that there must be a way as it seems basic but I cannot see
how it is done. Some advice would be appreciated. It has been
suggested that I put the subProcess B in a separate Pool and then call
it as a function but I do not understand this (that is not to say that
it is not the way it should be done of course).

[Alessio Dragoni]

The simplest way is to use a loop. This can be achieved using the OR join.
of course you must add a decision when you exit from the B step in order to evaluate if you need to proceed with C or E

see the attached picture for an example

Regards
Alessio

[Luca Tamburrano]

Hi,
I suppose that if for some reason your process needs to repeat some
steps maybe you could trigger this checking a variable.

So if you want

A->B->C->D->B->E

that could be modeled with 2 decision gateways at the end of
respectively B and D.

The gateway at the end of D is responsible to set the execution point of
your process backwards to B while the gateway at the end of B is
responsible to set the execution point of your process forward to E.

hope that helps

Luca

[mfe...@micron.com]