PTC Windchill Poorly Designed Logic for Calculated Associations between CAD and WTPart

[tcurry]

We are having issues with Calculated links and the flawed logic that PTC has used in how these associations are determined in some use cases.  One example that keeps coming up lately is when two drawings referenced a single CAD model,  so both drawings became "calculated" to the corresponding WTPart.

The users decide to move all the technical information to one single drawing,  so they revise everything and disconnect the latest version of one drawing from the model.  The model and desired drawing are checked in and will move forward.  The second drawing should be dropped and no longer considered.   But as you can see in the attachment illustrations,  the non-latest version of the disconnected drawing will remain displayed on the WTPart as calculated.  This makes no sense.

I have even gone so far as to create a new 3D model and new WTPart for the disconnected drawing.  That second drawing is linked to the new 3D model and therefore associated to the new WTPart.

Still,  the old version of the drawing remains listed as a "calculated" drawing to the first WTPart.  These items have taken different paths at the fork in the road and should not be associated any longer at the latest versions.   When you view the first version of the WTPart,  yes,  it should show.  It was related at that time.   Today?   It is no longer and should no longer be displayed.

Calculated links are poorly implemented.  Is there a way around this?

We are to the point that we are discussing generating "content" links for all current "calculated" drawings and then completely disabling the property that displays Calculated links.  Better to not have that feature if PTC can't make it work correctly.

[tcurry]

And it's not like it's a new topic.  I can find evidence of people complaining about the calculated links going back over 10 years ago.  Why does it take so long to fix something?

[HelesicPetr]

Hi @tcurry 

This is exactly the situation when the drawing should use a content link instead of auto-calculation

PetrH

[tcurry]

Hi, @HelesicPetr .
Using the Content link doesn't solve this issue.  The drawing which we are trying to disconnect and separate will continue to show "Calculated".

[HelesicPetr]

Hi @tcurry 

I meant that using the content link does not case your situation if you use it from the start.

You need to delete non latest iterations of the drawing, that point to the part. 

For example you can use purge function. 

PetrH

[tcurry]

I see what you mean.  Yes,  if we know from the very first iteration that the drawing may be revised without revising the model,  then we should use Content link on the Drawing from the beginning.  That way,  the intended drawing is shown on each revision of the WTPart.  Thanks.

I wish PTC had an answer for those thousands of legacy data that have already been released with their Calculated associations,  but also need to only have the drawing revised today or in the future.

[d_graham]

@tcurry 

FYI, it is possible to create content links to all iterations of the drawing after the fact without iterating anything. So it is possible to fix this by using content links.

[tcurry]

@d_graham   How would you do that without iterating the WTPart?  Adding this Content association would iteration each revision of that WTPart as far as I know.  And all those older revisions are already released / frozen.

[d_graham]

In short, I write code that tricks Windchill.

I’ve used this technique many times. It’s a good example of thinking outside the box.

<BR><BR>

[tcurry]

Ah, yes, we discussed directly generating the Content associations into the database,  but it was decided that this was not advisable for our system

[d_graham]

@tcurry 

Why was this deemed not advisable for your system?

Was the only option considered a direct dB insert?

I use supported APIs to create the links as opposed to a direct dB insert.

I’ve used this coding technique many times where the company did not want to iterate.

If fact, I just did this for a company that recently introduced WTParts into the fold and wanted to link the WTParts to existing WTDocs without iterating anything.

It works great and is much faster than using code that requires iterating. 👍

If you need help with this feel free to reach me at

windchill.developer@yahoo.com 

I’m always interested in new, fun projects.

David

[tcurry]

@d_graham 
Are you referring to Windchill 13?   One of my colleagues who has looked forward to the new version says that there is a new API to navigate the calculated links,  but we are just starting to learn about it.  Currently, all of our testing systems and our Production system are on Windchill 12.0.

What can you tell me about what you mean by the "supported APIs"?

Thank you

[d_graham]

@tcurry 

Per my post.

If you need help with this feel free to reach me at

windchill.developer@yahoo.com 

David

[GrahamV]

I agree, calculated links make big assumptions, they caused us a lot of confusion on our system so I disabled/hid the links a couple of years ago and now force users to associate drawings as Content. 

I think the concept of calculated links is a bit flawed in the first place, how can the system know which is the master drawing, when it can appear on multiple drawings as reference? Maybe they could provide some mechanism for selecting the master drawing from a list of calculated links, with an option to override if it doesn't find it, but i can't see it being much of a benefit over just manually adding the drawing.

[tcurry]

I understand the logic in that any drawing which has a CAD reference link to the 3D model is therefore somewhat dependent on that 3D model for it's drawing views.  So associating it to the related WTPart makes sense on the most basic use case.

What does not make sense is why the above described scenario still shows the non-latest version of the drawing on the revised WTPart even after the drawing was also revised and cleansed of any references to that 3D model.  A line was drawn ('in the sand") and the two objects parted ways.  PTC's logic in the display of Calculated drawings tries to incorrectly keep them associated.  The logic contains flaws and needs enhancement.