Since 2002 we have been running with Windchill tightly integrated to ERP, the only way to get a new “article/item/part/material” (use appropriate term depending on who you are talking to) in ERP is to create a WTPart and release it in Windchill. This integration also passes a lot of metadata, including version/revision and the Engineering BOM. This BOM is then controlled in ERP so that it has to be used as is and can be augmented at the location/branch level. In practice this means that the branch BOM is a level deeper than the Engineering BOM as it will include raw material and other consumables not shown on the Engineering BOM. We rely entirely on our Windchill managed Engineering Change process to automatically communicate the revision throughout the business, we have a closed loop ECN interaction with ERP to make sure this happens. We do not use Effectivity and are always build to latest Revision.
In regards to the Fit Form Function discussion, we have the policy (it is written down but cannot be system enforced) that any physical change to an item, or its BOM, as far as Windchill is concerned requires a revision. If the new revision will no longer be universally interchangeable with the earlier versions then it must be a new part number and the assemblies must be revised to swap out the components.
So if you need to edit something in CAD to modify or add a feature, or you are changing a dimension, or the material, or a surface finish, tolerance or coating, etcetera. Then you should be revising the WTPart and linked Documents to communicate that, same applies if you are editing the BOM in Windchill. If the changes you need to make do not modify the physical part or BOM then you do not need to revise it. Examples would be things like fixing spelling mistakes, adding a missing dimension or re-arranging a drawing to make it easier to read. We have an “I1” (iterate or informational) category of Engineering change to facilitate users making edits to released data without revising it. Due to our automated closed loop process on Revisions, they generate a lot of activity throughout the enterprise. We don’t want to trigger all that unnecessarily, so an I1 change is an efficient alternative for trivial corrections, clearly it is somewhat open to abuse though particularly if you have approver who just rubber stamps every change that comes across their work list.
All that said, the FFF change and new part requirement is only necessary when there is affected Assemblies/Inventory/Assets or Open Orders for those. So if the business has only built one of something, has no orders for any others, and an issue is found in assembly. Then it is acceptable to revise a component (not used in any other assemblies) and make edits to it that mean it would not be interchangeable with the earlier version. This is acceptable in this case because there is no impact to any other assemblies/inventory/orders. Clearly depending on how sweeping a change is being made and how much activity is involved in making it happen, there are various shades of grey between my black and white examples that are workable with sufficient engagement between Engineering and the rest of the business.
On all our manufactured parts there is a requirement that says something like “Mark Part No and Work Order number in this area”. The Work Order is the system of record in ERP for the production of this item, it gives the full traceability for an item from Raw Material through to final inspection. We also use full serialisation and Lot Control (which can be thought of as group serialisation) in some plants, but that is not really relevant to the discussion above.
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Lewis
