Applying a Property Name to an Item Flow in IBD

[Miguel]

Hi all,

I can't see how to do something in EA that I see in SysML diagrams referenced elsewhere.  I'm on EA15.1 build 1528.  Specifically, I'm trying to set up an Item Flow.  Here is what I am trying to do, which was accomplished via Paint:



I can only get close.  If I have the following BDD:



and then on the IBD for Containing Block, I create a flow connector, and try to select the item flowing, I only see the types, not the properties associated with my item flow:



I select Block1, and then specify to add the realization:



and what I wind up with is this:



It's an Item Flow, of type Block1, but I can't figure out how to make it look like this:



Any ideas?

Thanks,
Miguel

[KP]

ItemFlow has a tagged value called itemProperty. Set that to reference the Property.

[Miguel]

Thanks, KP... but I can't figure out how to do that.  I select the item flow, look at 'Tags' in the Properties but there are no tags specified.  How do I set the tagged value called itemProperty to reference the Property?

[KP]

You didn't select the itemFlow. There are two connectors between your Parts: the itemFlow and its realizing connector. The itemFlow connector is hidden automatically when you realize it so what you selected was the realizing connector. As it's not on the diagram, you will need to find it elsewhere, e.g. open the Relationships window and select one of the Parts...

[Miguel]

Hi all,

I want to get back to this topic.  I was never able to figure out a solution.  I tried to do the itemProperty tagged value, but there wasn't enough information to go on, and I couldn't get it to do anything.  I have since installed EA 15.2 build 1555; still can't make EA do what I'm trying to do.

Anyone have any ideas for how to do this (see original post)?

Thanks,
Miguel.

[qwerty]

Looks like the lowest pict in your OP shows the flow of an Instance. If have not much of an idea about SysML. ItemFlow is not an UML relation, only InformationFlow. And that conveys Classifier, not the Instance. Maybe SysML is different here, but from an UML POV this would be just wrong.

q.

[KP]

When you add a SysML item flow, you get the Information Items Conveyed dialog. Do not add any information items, and do not add a realizing relationship. Just click OK and then go to the properties dialog for the item flow connector where you can set the itemProperty tagged value. Then you can create an association or right-click an existing one and select Advanced > Information Flows Realized.

[Miguel]

KP, I really appreciate your continued attempts to help.  I just can't figure out how to map your words into clicks in EA that solve it.

Done: When you add a SysML item flow, you get the Information Items Conveyed dialog. Do not add any information items, and do not add a realizing relationship. Just click OK and then go to the properties dialog for the item flow connector where you can set the itemProperty tagged value.

Confusion: Then you can create an association or right-click an existing one and select Advanced > Information Flows Realized.

I tried this last part in a couple of different ways, but without getting the desired result.  There is probably something obvious that I'm doing wrong.  I'm sure if I were sitting next to you and watching it, I'd say "ooooooooh."  But short of that, I think I'm just going to live with it as it is.

Thanks, again.

Miguel.

[workingmatt]

Once you've got the itemFlow in place and its itemProperty tagged value set to a flowProperty you should see it as a dashed line with an arrow. This dashed line should show <<flowPropertiy>>name:flowProperty e.g. <<flowProperty>>i2:Electric Current.

Next create a Connector (solid line) between the same ports. Right click on that Connector, choose Advanced -> Information Flow Realized. This will bring up a dialog where you can select the flowProperty previously added. When you press OK, the dashed line itemFlow will disappear and roll up into the connector. The text that was on the dashed line will now be shown on the Connector. You can have multiple itemFlows realized to the Connector.

The traceability window does not display itemFlows on connectors. The Relationship View does not show itemFlows very well either. How does everyone interrogate itemFlows around the system - just graphically?

(I am not afraid to resurrect old questions if I have something useful to add!)

[PDC]

How does everyone interrogate itemFlows around the system - just graphically?

Essentially, yes this is how I would do it. If there's something useful to be communicated, then I draw a diagram to show it. Otherwise I don't bother drawing a diagram.

However, I also think of ItemFlows as part of the Interface Specification (and I'm sure I'm not the only one). So for example, to specify an interface between 2 Blocks, I would:
i. define 'data items' (using e.g. signals, Blocks etc) for all the signals in taht part of the system
ii. create my Blocks
iii. add Ports to the Blocks
iv. type the Ports using an InterfaceBlock (and conjugation for the opposite one)
iii. define flowproperties on the InterfaceBlock that are Typed by the 'data items' created in step (i) above
v. draw ItemFlows and Connectors between my Ports, and use my 'data items' when I select "Information Flows Realized"

I would then use my diagrams and tables of flowproperties & 'data items' to generate an interface specification (ICD) type document as would normally be requested by a customer. For any given Connector between 2 Ports (i.e. one specification of one interface), the ICD will list only those ItemFlows (and thus only those 'data items') that pass over that particular interface.

There's nothing novel or unique in all that. And some of it is just 'the way that EA does it' rather than perhaps a more grammatically-correct version of the SysML spec. But as you requested, this is how I do it