When working with a structured, level-wise Bill of Materials, there are cases where you need to assign alternate part numbers to specific components. This process requires careful formatting to ensure that the system correctly associates alternates with the intended BOM lines.
This guide outlines the correct steps for loading alternate PNs into an already exist BOM in the system.
Step 1: Identify the Target BOM Lines
Let assume the BOM is already present in the system looks like below: 
First, identify the specific BOM lines where alternate part numbers need to be added. In this example, these are highlighted with yellow.
Step 2: Prepare the Alternate PN Upload File
Create a BOM file specifically for uploading the alternate part numbers. The structure of this file must match the system’s expected format:
- Include all columns (Level, BOM Line#, Qty, Mfgr, MPN, Part class, Customer PN or Internal PN) required by the BOM import process (as shown in screenshot).
- Define Qty for each alternate part as 1. This value is required for upload but does not affect the actual quantity of the original part.
- Most importantly, ensure each alternate part entry includes the correct upper-level reference. The system uses this hierarchy to determine which main component each alternate belongs to. If the upper-level link is incorrect, the alternate will not be associated properly.
⚠️ Note: If the hierarchy is not respected or required columns are missing, the upload may fail or associate alternates incorrectly.
Step 3: Upload the Alternate PN BOM File
Upload the prepared file containing the alternate PNs. The system will match each alternate to the appropriate main component based on the structure and hierarchy provided in the file.
A successful upload will display the alternates below the correct components without altering the existing BOM structure.
Summary
To load alternate PNs into an existing structured BOM:
- Identify which lines need alternates.
- Prepare a properly structured file with:
- Qty set to 1 for alternates
- Accurate upper-level references
- All required columns (Level, BOM Line#, Qty, Mfgr, MPN, Part class, Customer PN or Internal PN).
- Upload the file into the system.
By following this method, you can effectively add alternate parts while preserving the integrity of your level-wise BOM.