I often go through the Agile PLM SDK group in LinkedIn. On a recent visit, someone was having an issue with obsolete parts showing on the BOM of an item on a change order. To be clear, the issue is not that parts on the change were obsolete, it is that parts on the BOM of the affected items of a change were obsolete. A process extension (PX) was proposed by another group member to remedy this business rule. This blog illustrates the implementation of that process extension.