Newbie Confused: Cannot find Exisiting Diagram in Sub-diagram popup


Beavering away all weekend, creating my first model with about 20 diagrams so far (mostiy Activity)

I have one diagram which I’ve successfully set up as a sub diagram to another

However, when, later, I try to use it, again, as a sub-diagram to an entirely different diagram (all within the same project) it doesn’t appear in the list of available diagrams. Yet if I use the “switch” button, I can see the required sub-driagram right next to the one in which I need to call it as a sub.

The only thing that is different about the “shy” diagram is that I’ve named it with parentheses at the end
eg procedure_name()

I’m wondering if this might have confused VP. It’s certainly confused me!

Possible Bug adding sub diagram

That sounds like a rather complex project!

I think I see what’s going on… When you create a diagram as a sub-diagram (or if you re-assign it) then this diagram will be moved within your environment to reflect on the new change(s). Note moved; so if you have a diagram A which has a sub-diagram B and you later re-assign B to be Z’s sub-diagram then B will be moved and placed underneath Z and in he process it gets unlinked from A.

So: a sub-diagram is really just that: a diagram linked and placed ‘underneath’ a certain element.

If you want to create a relationship between certain diagrams then it might be a better idea to use the reference option instead. It sits directly opposed of the sub-diagram option. The sub diagram option sits in the lower right corner of a model element whereas the reference option sits in the lower left corner.

This option allows you to reference (“link”) other diagrams but without physically moving them to a new location. And the best part: you can still navigate from one element to a related diagram, the main difference is that you’d now use the option on the lower left.

I’m pretty sure that this is what has happened on your end but I’ll also test with renaming a diagram using ()'s to see if that somehow influences Visual Paradigm. It’s always useful to try and reproduce a possible bug :slight_smile:

Hope this helps.


If you want to create a relationship between certain diagrams then it might be a better idea to use the reference option instead.

Ouch! I must have created several dozen such links using the sub-diagram option. Is there a quick way to change them all to References?


I’m not aware of an option to “mass change” this but personally I also wouldn’t worry about it too much. Why not use both options for now? I’ll explain in a second, let me first answer that which I do know…

Although I’m not aware of an option to change this “en messe” there is an easy way to get a good overview:

  • Open the ‘view’ toolbar, click on “Panes” and then select “Diagram navigator”. Note that you can only do this with a diagram open, so not within the project browser.
  • Now find the “folder” icon in the icon bar, all the way on the right. Click it the small arrow next to it and switch to “diagram hierarchy”:


Ok, that came out a bit bigger than I wanted, but it’ll do. When done click on the first entry (the root note, probably called “trunk”). Then click on the small arrow next to the “collapse” option and select “expand”, this will expand everything. Warning: on larger projects this could take a little moment.

This will allow you to quickly spot all the underlying diagram relationships:

I marked the expand option here

If you look at the screenshot above you’ll notice 2 diagrams being linked: ‘Review preparations’ and ‘Writing a post’. So that’s a good way to tell that one (writing a post) is a sub diagram of the other.

So back to my suggestion…

Why not use both options for now? So leave everything as is, go over your project and the moment you notice that you need a link with another diagram then simply add that link by creating a reference.

See, if my theory is correct then you probably won’t have as much links as you think. Because as mentioned above: every time you assign an existing diagram to be a sub diagram then this diagram will get moved and unlinked from its previous diagram.

Hope this can help!


Looks useful but will need to explore a bit further before I grok its capabilities here.

One thing in particular that I’m finding difficult, is “moving” a diagram I’ve accidentally created in the wrong place and putting it in the right place. Thought for a moment the “diagram navigator” might help with that. The Project browser isn’t particularly helpful in that regard because while you can see - and move - all your diagrams, it’s not obvious, in that context, where they sit in the hierarchy. The navigator lets us see the hierarchy but not move anything…


Makes perfect sense. Therefor it might be best to just leave things as they are and from here on use the reference feature if applicable. That should help to prevent things from becoming too complex.

I don’t have that problem myself but then again I’ve also been using this software for so long that I got used to that. I definitely see your point though, the project browser only shows you one specific part of your project.

And then panes can be very useful.

True. Panes can be very useful for dragging items into your diagrams but it gets a bit tricky when you try to move stuff inside the pane itself. But there’s a way around that:


Click on a model with your right mouse button, hover over the sub diagrams option and select existing diagram. Then select the diagram(s) you want to move and click on, done.

Best of everything in my opinion: you keep full overview, you’re always in full control and it’s also fully safe because you don’t have to rely on dragging and dropping and accidentally dropping something in the wrong place.

Hope this can help!


Not grokking that.

Surely what you’ve described is just the way to add a subdiagram to an element (which is what I’ve been doing instead of using the reference option) but I don’t see how that “moves” anything. Or, if it does, doesn’t that upset some other drawing if I’ve also used said subdiagram in one its elements?


Well, that’s how we started the thread :slight_smile:

When you assign a sub diagram you’re placing it “underneath” the model element you assigned it to (within the whole hierarchy). So if you re-assign a sub diagram to another model element (for example a model element in another diagram) then you’re effectively moving it.

I’d say give it a try and you’ll see.


I think the problem is that I don’t see “evidence” of a move. In fact, I haven’t been able to find a view which displays the hierarchy you mention. I’m expecting to see a kind of tree structure with top level diagrams and their sub diagrams below them. Is there such a view? and, if so, how do I access it?


You can switch to Diagram Hierarchy view in the Diagram Navigator.


Thanks Peter
(how weird - couldn’t post that without adding enough characters to exceed a min 20!)


Thanks. The “at least 20 characters” is a default setting.
We just adjust it to be minimum 10 chars.