Managing Variation (Windchill, Creo, and ERP System)

[TomU]

I am looking for suggestions on how to manage variation in Windchill, Creo, and our ERP system. The variations in this case are things that don't affect form, fit, or function. These may include material type (M2, D2, S7, Carbide), hardness (Rc), and coating (TiAlN, TiN, etc.).

So far I’ve managed to identify the following possible approaches:

1.) Track variations by revision (single model and drawing for all variants)

+ Only one model and drawing are required.

- Assemblies are going to load the latest (or as stored) revision. No easy way to choose which variant is used in the assembly.

- Geometry changes will require an entirely new set of revisions (equal to the total number of variations)

- Everyone is currently trained to only order and build to the latest revision.

2.) Duplicate the model and the drawing for each variation

+ Traditional way of working

+ Model and drawing are not dependent on any other objects

+ No special PDM or ERP functionality required.

+ CAD drawing shows exactly what the finished product should be

- Harder to keep duplicate models up to date

- Not part of the original parent assembly

- Variants are not referenced by other assemblies (required or where used)

- Each drawing has its own revisioning scheme

- Any geometry changes made to the original model have to be manually made to all the derivative models.

- Harder to track order history in ERP system (different objects)

3.) Duplicate just the drawing, but reuse the same model

+ Changes to the one model are visible to all drawings

- Have to manually update each drawing separately

- Drawing numbers would need to be different than CAD part numbers.

- Not every drawing would have a cooresponding model of the same name.

- ERP system would need to order by drawing number.

- Assembly would only show original version. Could not 'use' derivitives.

4.) Duplicate the drawing and make a family table out of the model

+ Essentially the same as #2.

- Ditto.

5.) Remove the attributes from the model and drawing and assign these in Windchill (and ERP system)

I’m guessing this would require using multiple WT parts linked to the same CAD model. If there are unique representations generated for each WT part, and the custom attributes could be watermarked onto the drawing, then we would theoretically be able to create all the variants without needing to make any changes to the CAD models or drawings.

+ Only one model and drawing are required.

+ CAD model and drawing don't have to be changed to create variants

+ Assembly is guaranteed to show correct version (there's only one)

+ Traceability in ERP will be across all variants (this is good).

- Variable attributes are not visible on native CAD drawing. Published representation has to be used instead.

- WT parts have to be created, used, and managed. Major user training.

? If the CAD model is changed, will all the different WT parts linked to it automatically update republish?

I should probably add that we currently use Windchill (PDM Link) as simply a file vault. We don't use WT parts, leverage the representations for any business processes, or have any workflows/release processes (in Windchill). We also are very Creo centric, meaning most users will almost never access Windchill outside of the embedded browser in Creo.

Thanks!

[GregoryPERASSO]

Hi ,

my opinion.

5 is the more elegant. But lot of work as you only use wc for CAD vaulting

the answer is yes. modifying the CAD update all the WTParts (regarding the access policy rules of your user)

1 you can forget

may be a 6 (between 2 and 4)?

family table but not duplicate drawing

regards

[kpritchard]

If you want to determine which variant goes into a given assembly, then a unique ID (Part Number) for each variant would be required. I'd recommend this as a best practise beyond Fit, Form and Function - think in terms of troubleshooting a failure and the potential for an unanticipated failure with material as root cause. If you do not differentiate between materials, you'll make it almost impossible to make the connection between failures and material differences.

From there I would use a Multi-Detail approach for the Drawing and describe all material variants with shared geometry on a single Drawing. Models could be Family Table Instances, (or not). Each variant could get a WTPart, but does not need to. Each variant would get a unique Item Number in your ERP (if you were using them, the WTPart would be equivalent to your ERP Item. This has the added benefit of ensuring that geometry (and other) changes get applied to all same-but-different Items.

Given the commentary around use of WTParts, my guess is that the paradigm is still one of "CAD as primary". Recommend a shift in thinking to WTPart as primary, with CAD describing the WTPart (digital representation of "the thing"). You don't have to start using WTParts as the approach is beneficial even in a CAD (Creo) centric environment.

[TomU]

I fundamentallly do not understand the benefit of duplicating our existing CAD structure in Windchill as windchill part and items. We are a metal stamping company. Engineering designs the tooling, creates the drawings, and releases it to be built. Once the tooling is built it is used by our manufacturing department to stamp parts. Each tooling design is unique and is entirely controlled by Engineering. To some degree, the rest of the company is Engineering's customer. From what I've seen of Windchill parts, it seems like we would be adding a huge amount of complexity to how our designers have to work, and I'm not sure for what. What am I missing? Why create Windchill parts, items, and BOMs if there isn't a demand by other people (outside of the department) for the information?

[dschenken]

If there is no difference between parts with different materials, hardness, and different finishes, just make them options from a list on the drawing. One drawing, one part, one ERP record.

There is at least 50 years of research into part variation tracking. Here's a link to a section of a book on just this subject.

http://books.google.com/books?id=s3Cbw4sJWBYC&pg=PA241&lpg=PA241&dq=erp+part+number&source=bl&ots=RduWMjsHA6&sig=ynzHFN0gyLTB2HR_TPntYUdoS5A&hl=en&sa=X&ei=Vi0FVPySDYnzgwSKi4DoDQ&ved=0CIMBEOgBMAk#v=onepage&q=erp%20part%20number&f=false

ERP: Tools, Techniques, and Applications for Integrating the Supply Chain ...

By Carol A Ptak, Eli Schragenheim

Publisher http://www.crcpress.com/product/isbn/9781420056020

[TomU]

If there is no difference between parts with different materials, hardness, and different finishes, just make them options from a list on the drawing. One drawing, one part, one ERP record.

To do that we would need to identify all possible options at the time of drawing creation. The potential matrix could be huge, and would require updating the drawing any time a new material or coating type became available. That duplication/updating is the very thing I'm trying to avoid.

I read the book excerpt you linked to, and I would say that each of these variants do need to be uniquely traceable, but I'm not convinced that also means they need separate part numbers.

For example, every order (order number) is unique. It has a unique due date, quantity, and possibly even vendor. On the other hand, many different orders will exist in the system for the same part number. If material, coating, and hardness were tied to the order itself instead of the part number, the uniqueness is still captured without needing to create a bunch of duplicate part numbers.

Regardless of whether the uniqueness is captured in the ERP system by the order number on the fly, or by the part number prior to ordering, the trick is figuring out how to get the print to show the selected options without creating every variation in advance in the CAD system. I'm pretty confident I can get the ERP system configured to handle the options, I'm just not sure how to best setup the CAD/PDM system.

[GregoryPERASSO]

WTParts are the gateway/interface between the strict "as design/CAD structure" View , and the xBOMs views.

May be your Stamped Parts business ( do you mean you only manufacture single parts ? without assemblies (except your tooling ?)) does not need to manage manufacturing BOMs. with several mBOMs levels (ie stock points that need several Manufacturing orders do be built)

Anyway, you're right.... the goal is not to duplicate CAD structure and trying to manage all the matrix of options.

But I think you can not do that regardless of your ERP implementation if you want to integrate both systems...

Creo has new capabilities to build "150% CAD structure" with basic options choice . And these new capabilities are align with the Options & Variants WTparts functions (advanced configuration and logic).

If your ERP is already set to manage "the uniqueness" through Part Number + Order (which I assume handle options or instance characteristics) , may be you should investigate this way ?

regards

[TomU]

WTParts are the gateway/interface between the strict "as design/CAD structure" View , and the xBOMs views.

I guess that's the difference. We don't use (or need) any other BOM views besides the CAD structure.

May be your Stamped Parts business ( do you mean you only manufacture single parts ? without assemblies (except your tooling ?)) does not need to manage manufacturing BOMs.

Yes, the company primarily stamps individual parts. These are not created or managed in the Windchill PDM system. (They are completely managed in the ERP system.)

The tooling we design are complex, unique assemblies, and their BOM is directly used by the tool build deparment to order, produce, and assembly the finished tooling.

Creo has new capabilities to build "150% CAD structure" with basic options choice . And these new capabilities are align with the Options & Variants WTparts functions (advanced configuration and logic).

Can you point me to any documentation that discusses this (in Windchill)? I'm not sure exactly what I should be looking for.

Thanks!

[GregoryPERASSO]

The Creo side is the called "Option Modeler"

Here's a video (sorry in french)

Creo Options Modeler : https://www.youtube.com/watch?v=sFTMH0EMXCc

but you should find something on PTC web site

The Windchill Side is called "Option and Variants", . Search for Configurable Parts, ATO, CTO , but not necessery well documented .... except may be online help.

Basicaly with Creo "standalone" , you can build overloaded 150% CAD structure. and be able to display needed modules by "just enable them" without particluar logic. You can also generate an assembly instance of a particular Configuration (a kind of save as , with no relation to the original overloaded ASM. So no easy modification like a family table)

Windchill O&V give you ability to define advanced logic on Options. And this logic, apply to the WTpart BOM , is able to drive the associated CAD structure

You can also persist and manage "Variant Spec" , which is the Option list used to filtered out the Product Strucuture of a particular instance (for example a purchased Variation for a particular client)

[dschenken]

It sounds as if you don't have a part drawing - you have a pattern drawing. Just create a drawing of the shape and let the ordering system manage everything else. There is no need to put any of the variable information on the drawing. The customer for the part already knows what he wanted and the product you ship will include what you did as part of the shipper.

I suggest the ERP system create a unique number so that the customer can order the same options again and get the same number for his own system to track.

I was suggesting you buy and read the entire book.

[TomU]

It sounds as if you don't have a part drawing - you have a pattern drawing.

Maybe....but this "pattern drawing" may be sent to our internal tool room, local suppliers, or even to suppliers in China. Once it physically leaves our building it becomes much more critical that all requirements (and options) are included on the drawing. The machinist actually building the tool may never see the physical PO, cover sheet,etc.

I was suggesting you buy and read the entire book.

I'll see what I can do. I haven't even finished the "Engineering Documentation Control Handbook" yet! (Maybe that's my whole problem.)

[GregoryPERASSO]

FYI

We've got some "pattern drawing" , linked to several WTparts (which may vary on color , coating or hardness like you).

And the Drawing is dynamically watermarked and PDF printed "as needed" with a combination of CAD drawing + part information.

the result can be different depending of PDF usage: internal shopfloor usage, etrenal purchase, etc ....

[TomU]

This sounds exactly like what I am considering. What type of association do you have between the single cad model and multiple WT parts?

Is this functionality part of this: http://communities.ptc.com/message/248564#248564

Is there anything special you need to do to get all the "child" WT parts to republish anytime the parent CAD model changes?

Having never used WT parts or change processes, will a change request or change notice automatically collect the necessary "child" WT parts when the CAD model is selected for a change?

Thanks!

[GregoryPERASSO]

Is this functionality part of this: http://communities.ptc.com/message/248564#248564

Yes it is !

Tom Uminn a écrit:

This sounds exactly like what I am considering. What type of association do you have between the single cad model and multiple WT parts?

Drawings are linked with "content" link which is a n to n, version to version Describe link.

3D CAD model are linked with "owner" link. the functionnality above authorize n to n link

formally these links are owned by the WTpart. The CAD are "more" the childs ... Windchill is WTpart centric. And CAD is only a "descriptive" doc. Even surely the most important one

Having never used WT parts or change processes, will a change request or change notice automatically collect the necessary "child" WT parts when the CAD model is selected for a change?

Not necessary need of Change managment. The Chnange Mgmt will track the impacted datas. there's a collector that allow to collect all WTParts from CAD , or vice versa all related CAD from WTpart

WTparts by default are automatically updated through the owner link (attribute, PView viz or BOM structure) on CAD checkin. but some cases need manual action if you have more than one WTpart as child to one CADDoc. This can be set to be always manual (no auto synch from CAD to WTpart) by a pref