Use of non-latest version in a product structure

[Dana1]

We have a situation where a subcontractor has delivered Rev A of a part which we have tested and are now ready to incorporate into the system we will deliver to our customer. 

In the meantime the subcontractor has continued work on the product and has delivered the part with added functionality, but have delivered it as Rev B with the same part number, ready for us to test.

However when we go to add the part into our overall product structure there is no way to select a specific version of the subcontractor part; that is, because Rev B is now in our PLM system there doesn't seem to be any way for us to add Rev A into the product structure.

Does anybody have any way around this, or thoughts on what we can do?

[BenLoosli]

Open the Rev A parts in Creo first, then open the assembly. This will create the assembly links to the Rev A components.

The caveat is that you will need to open the assemblies with the As Saved option in the future until you have upgraded the assembly structures to utilize the Rev B components.

[Dana1]

Thanks Ben, unfortunately these are not modelled in Creo.

[BenLoosli]

Should not matter, as long as you have the rev A and Rev B in your PLM system as the same number but different revisions, it should still work. If they are in PLM as unique objects, you will need to create 2 upper level assemblies for each component revision.

[Dana1]

Ok, we have tried this, but we are not sure what As Saved function you are talking about, can you explain this a bit more please?

[BenLoosli]

When the file structure of an assembly is created, Windchill knows which Version of the component is used to crate the assembly. When a new version is added to Windchill, the CAD software doesn't know about it, but Windchill does. By default, at least with Creo, when opening an assembly which has a revised component in it, the latest version of the component will be loaded. There are 2 ways around this. One is to explicitly load the older version file in memory before loading the assembly. The other is to download to your workspace with the advanced options and there you can choose between Latest and As-Saved for which components get loaded into your workspace.

[Dana1]

We have been through the steps as suggested, but the connection always moves to the latest Rev. We have changed to creating them as new parts rather than as revisions which resolves the issue.

[Henrik_F]

Hello.

We have a similar problem. When revising a WTPart it replaces all the occurrences with the latest revision in the BOM structure. I.e. if the BOM is on revision 5 and a part it contains is revised from 1 to 2. All previous revisions of the BOM are updated to use revision 2 of the part. Is there anyway to hinder this behaviour? Otherwise there is no big point in revising BOMS if it only can keep track of objects without any revision information.

//H

[Dana1]

Hi Henrik, agree - I expected that once a WTPart was released that its BoM would be fixed and it would need to be revised for any subsequent lower level part changes to be included. Having released parts just change on their own is not what I would consider good practice.

[Henrik_F]

I sort of figured out the logic and how PTC wants you to use BOM:s after a lot of digging. The version of a BOM only seems to keep track of the objects in it in a strict form fit and function manner. So that if it has the same number it is considered to always to be the same and always will pick the latest. The only way to keep a historical record of BOM:s seems to be trough a baseline so that you capture all parts at a certain time and then you need to filter your BOM structure in the explorer using that baseline. 

[GrahamV · Accepted solution]

This is fundamental to how BOMs work in Windchill, a BOM structure only controls the number of the child part, not the version, e.g. WTPart A10001 V1.2 may contain child WTPart B20001, no version is recorded for the child. If you wish to control the version of children, you have to use a filter method like baselines (a snapshot of part versions) or effectivity (typically a date or serial number from which a version comes into effect). The default filter is 'latest', which is why you always see the new version when revising.

Note, CAD documents usually have an 'As Stored' configuration that others have mentioned, this does record the child version, however it's not much use in the context of a BOM.

[Dana1]

Thanks for the response, it makes sense for most parts. One quest though - how do you manage Software as part of a BOM, which typically is managed by version number to indicate functionality change?