ManufacturingKnowledge

Managing EBOMs-MBOMs

Realign MBOM and EBOM assemblies

If your MBOM is significantly different from the linked EBOM from which it derives, it is possible that links between the two, as well as their properties, may become accidentally broken due to changes in the EBOM, MBOM, or both. This loss of equivalence criteria results in unreliable results when you run an accountability check and breaks the Find in other Structure function.

In many cases, you can fix the equivalence criteria in the EBOM and MBOM by aligning their properties so that the accountability check reports full matches. If parts have moved in either structure, this action also realigns their transformations.

Procedure

  1. If the EBOM and MBOM are not already linked, link them using the Link Associate→Link Structures command.

  2. (Optional) If you are viewing unconfigured structures, turn them off so that you have 100% BOMs by deselecting the show unconfigured toggles.

While you can run the alignment without fully configuring the structures, not all lines may be aligned.

  1. Select the top line of the EBOM and the top line of the MBOM, and choose Tools→Manufacturing Alignment→Align.

In the Align dialog box, your MBOM appears as Line to be aligned and your EBOM as Line to align with. By default, the command is set to align the selected assemblies (EBOM and MBOM) and all children of the selected top lines.

  1. To align all properties in MEAlignedPropertiesList site preference, with the exception of reused assembly lines, select the Align properties (for non-reused assembly lines) check box.

  2. Click Align.

An Alignment Summary prompt reports on the success of the cammand and the number of lines that were not aligned.

  1. To view the alignment log, click Yes; to continue without viewing the log, click No.

The alignment log reports reasons for line alignment failures, such as multiple equivalent lines in the EBOM.

  1. If multiple equivalent lines are identified, identify which are correct and rerun the align command on those selected lines only.

  2. Run an accountability check to verify that the structures are aligned.

Source: https://docs.sw.siemens.com/en-US/doc/282219420/PL20251212545240207.xid1364469/xid1116452 · retrieved 2026-07-11