EA10 BPMN2 Business process sequence flow join err

[Karl M]

HI All

I have just upgraded to EA10 and started using BPMN2 so this could just be a case of user error.

When I attempt to join a business process using BPMN 2.0 tools to another object via a sequence flow I get an error "Invalid Target for the sequence flow" or Invalid Source for the sequence flow". This does not occur if I switch back to BPMN 1 tools and do the same thing.

Is this a bug or just a syntax difference between BPMN 1 and 2?

[Matt Taylor]

No- I think there is a general issue.  We have been using BPMN 2.0 also with V9.  The validity checking is different between 9.3 and 10.  the issue we get is that trying to edit v9.3 diagrams in 10 crashes the system.

[Eve]

Version 10 added validation for connectors for BPMN 2 diagrams.  BPMN 1 does not include validation and is unlikely to have it added.

The reason for the error is that a Business Process element is not a valid element for a Sequence Flow connection.

As per BPMN 2.0, Sequence Flow's source element and target element MUST be from the set of the following Flow Elements: Events (Start, Intermediate, and End), Activities (Task and Sub-Process; for Processes), Choreography Activities (Choreography Task and Sub-Choreography; for Choreographies), and Gateways.

[Eve]

Matt, yes the validity checking is different between 9.3 and 10 (now implemented) but I have not seen any case of crashes.

Have you sent in a bug report?

[Matt Taylor]

Some questions:

1.  Are <<Business Process>> elements not just stereotyped activities?
2.  If not, where do they appear in the BPMN 2.0 standard?
3.  Of what use are they if you can't connect them to anything?
4.  Are you going to supply a script which will fix now invalid diagrams or expect users to rebuild their entire library?

[Matt Taylor]

Simon - yes I have submitted a bug report.

[Doug Blake]

Some questions:

1.  Are <<Business Process>> elements not just stereotyped activities?
2.  If not, where do they appear in the BPMN 2.0 standard?
3.  Of what use are they if you can't connect them to anything?
4.  Are you going to supply a script which will fix now invalid diagrams or expect users to rebuild their entire library?

I am new to BPMN but my first diagram fell foul of this problem. It seems to me that if the validation is present when you try to add an association link, then that validation should be accessible later from the menus. I had a diagram that used Business Processes and Activities with sequence flows. I cant add any more sequence flows and the ones that are there break BPMN2.0 rules, so wouldnt it be nice to be able to validate the model and at least get a list of incorrect associations.

All I get with CTL-ALT-V is "No errors, No Warnings" Just what is that command for?

[Eve]

A BusinessProcess element in Enterprise Architect comes from the Process class in the BPMN specification. The inheritance chain for this is CallableElement, RootElement and Base Element. The specification uses this as a diagram as you can see from the quotes below. Enterprise Architect has introduced an element to hold the properties of the Process.

"In BPMN a Process is depicted as a graph of Flow Elements, which are a set of Activities, Events, Gateways, and Sequence Flows that define finite execution semantics (see Figure 10.1)."

"Note that BPMN uses the term Process specifically to mean a set of flow elements. It uses the terms Collaboration and Choreography when modeling the interaction between Processes."

A sequence flow is a link between two FlowNodes. In the description of a sequence flow in the specification you will find that "Only the Gateway, Activity, Choreography Activity, and Event elements can connect to Sequence Flows and thus, these elements are the only ones that are sub-classes of FlowNode." This is the rule that was implemented in version 10.

To model a sequence of processes in a conformant way you would create CallActivity elements referencing the process.

To do this in Enterprise Architect:

• Create an Activity
• Set the isACalledActivity tagged value to true
• Set the calledActivityRef tagged value to the Business Process Element

However, it's obvious that there are many users having this issue. Our goal is to make it easier to make a model, not harder. We are planning to release a patch for version 10 that will allow Business Process elements to be directly connected using a Sequence Flow.

[Matt Taylor]

So a business process is effectively (in UML terms) a package?  Makes sense.  From a user perspective - (actually from my perspective), a more useful script would be to change business process elements into activities with compostite diagrams.....

[Eve]

You're on the right track.

In UML terms it is the equivalent of Activity, StateMachine and Interaction.

An Activity is defined by the Actions, Control Flows and Object Flows it owns. While it can be called from a CallBehaviorAction (or a state entry etc)

A StateMachine is defined by the States and Transitions it owns (via regions). It can also be "called" (although it's the wrong word to use here) by a SubmachineState.

You get the idea I hope.

In pure UML you'll always find actions inside an activity, and states inside a statemachine, but EA implicitly allows you to just use a diagram as the same thing. Try exporting a package containing a single action to XMI 2.1 to see what I mean.

In BPMN the same applies. There is always a process wrapping your diagram. You can export a simple diagram to BPMN 2.0 xml to verify this.

If you have used them as Activities solely then you can certainly write a script to convert them to activities. It wouldn't be hard effectively I would set StereotypeEx to "BPMN2.0::Activity".

[baran]

Dear Admin,
I'm new to EA too. I did the 3-step solution you've suggested. unfortunatly I didn't get the appropriate result   , Actually I want to have a sub-process among my activities and could click on it to enter a sub-process.
I would be glad if you could help me.
Regards
baran

[pgmatos]

Simon M.

I think you ought to recognize that this is a serious bug/misconception, one which compromises the development of BPMN 2.0 Choreography diagrams.

pmatos

[Eve]

The current build of EA already allows you to use Business Process elements on a Business Process diagram.

[pgmatos]

You do not answer my remark.

The current build of EA does not allow you to create a 'Sequence Flow' between, for instance - since the problem arises between several other Elements of a Choreography Diagram -, two 'Choreographies'. The error 'Invalid Target/Invalid Source' is displayed.

pmatos

[Eve]

pmatos,

Until your last post no-one had said that you could not connect Choreography elements (or more precisely Choreography Tasks.)

The latest build has addressed that error.