We have just recently got familiar with External Simplified Representations in order to keep our upper assemblies clean and free from orientations, cross sections and simplified representations that are mainly created for the drawings. External Simplified Representations offer a solution to organize each rep, orientation, ... specifically for each drawing. And that's a good thing.
In our assemblies, especially lower level sub assemblies, we have created user defined simplified representations where smaller parts are excluded, general parts are in geometry representation and even some parts are in a specific representation excluding complex features. That saves us quite some time when defining a simplified representation of higher level assemblies, where you can re-use the simplified representations available on lower level assemblies.
We noticed however that when defining an External Simplified Representation, you cannot reuse the lwoer level user defined simplified representations. Given the theory behing ESR's where you don't open the complete assembly but have a notion about the relations etc..., I can imagine it 's far more complex to use user defined reps compared with the default geometry, graphics, master reps, but still I cannot see a reason why is shouldn't be possible to reuse the existing simplified reps.
It is particularly inefficient when there are assemblies that are present numerous times in the modeltree.
One work-around we've been introducing is loading the complete top-assembly in graphics or geometry rep in the ESR, and then in turn create a simplified representation of that particular ESR. In the modeltree for example, we can use predefined simplified reps of sub assemblies and then save the newly created simplified rep into the ESR. This comes pretty close to reusing predefined reps in External Simplified reps, but is quite complex and doesn't offer the full benefits of ESR's. Furthermore, I don't want to be the person in charge of training new employees and explaining "you have to create a simplified representation in an external simplified representation in order to reuse predefined simplified representations".
I so want to see how this was written into the ESR specification
I did see an SPR on custom templates having a bug related to ESRs that was resolved in Creo 2.0 M070.
What version are you running?
We are currently still on Wildfire 5.0 M210, but have learned from our reseller that :
"...this is still the case in Creo (version not specified). We have found that when you create the simplified representation in the actual top assembly without checking out, it's possible to re-use user defined simplified reps. You can then "Copy As External" with the actual lower level user defined reps used correctly. Therefore this issue seems related to the UI."
Yes unfortunately! Seems it simply has not been implemented yet.
An SPR is open and there is an article about this limitation in our database:
CS190092 : User defined simplified reps of sub-assemblies are not selectable when creating a new External simplified representation assembly in Creo Parametric
So you cannot specify them in external simplified rep and as a workaround you use internal simplified rep as to select them and then create an external from the internal simp rep.
While capability to reuse user defined simpreps from design assembly in Definition Rep of ExtSImpRep is really missing, this is easely workaroundable issue now. There is an option to create ESR - own simpreps (besides Definition Rep), where container subassemblies user defined simpreps can be definitely used.
In ESR, create new simprep / see "user defined" will appear for subassemblies. ESR - level simprep can be used for File / Open Rep (of ESR) and anything else. So: create ESR from Master Rep of top assembly (or whatever rep you want), open ESR , create its own simprep, use User Defined from subassemblies.
The only benefit of having User Defined in ESR Definition Rep (which is actually ESR content definition) is in eliminating PDM dependents download when checking out ESR. Definition Rep will not bring anything beyond what's in it, while ESR level simprep can not be used for PDM actions - it is transparent for PDM as any regular simprep.
Is this something that has ever been 'fixed' in creo6?
absolutely ridiculous that i need to create a simplified rep of an external simplified reps that want to look at simplified reps.