Let's face it: no one wants to do PCB design reviews. I do plenty of one-minute design reviews for the Altium Academy YouTube channel, but I don’t enjoy going through grueling, multiple-hour meetings reviewing a PCB or a set of schematics. In a PCB design review or schematic review, these documents are the stars of the show, and they are certainly areas where errors crop up in designs. However, there's another area where a review needs to be performed, and traditionally no one performs this review until they are about to order parts.

Design teams also need to manage their supply chain by performing a BOM review. This is not about reviewing components and libraries to ensure they have correct descriptions or footprints; this is about ensuring your parts can be sourced at the required volume. In some cases, failure to check for inventory will completely derail a project, as it may require a part swap that demands a significant redesign. To help keep client projects on track, we leverage our design tool capabilities, broker network, and distributor websites to quickly get through a BOM review and identify parts that need changes before reaching the end of a project.

How a BOM Review Works

When performing a BOM review for a PCB project, the BOM will need to be exported periodically and looked over to identify any problems with line items in the BOM. At a minimum, a BOM review should be performed after the schematics are finalized, but before PCB layout begins. This is an ideal time to check vendor inventories and pricing to ensure that your original design can be procured at your required quantity.

Broadly, a BOM review involves checking the following details for each line item:

• Manufacturer part number that matches the package or footprint
• Supplier part number and the supplier name
• Brief description of each component
• Markings for DNI (Do Not Install) or consignments
• Any alternative supplier part numbers, as applicable

This covers both the assembly information and the sourcing information needed to complete your PCBA. You can include other information in your BOM export from your PCB design software, such as part descriptions and library footprints. In fact, to aid other parts of a design review, such as a PCB layout review, I recommend exporting these two additional pieces of information as they help ensure the specified part is the correct one placed in the PCB layout.

Depending on the capabilities in your PCB design software, you can run through a BOM review in different ways. Of course, the operative difference here is the time required to complete the review. If incorrect parts are found, or parts are found to be unsourceable, design changes will be needed, but it's best to find these issues earlier in the PCB design cycle, as this will reduce the size and scope of any required redesigns.

Leverage Electronic Component Distributor Websites

Some distributors have very good order creation tools that you can leverage for a BOM review. These tools allow you to create an order by uploading your BOM, and the tool will automatically identify out-of-stock or obsolete components. Of course, you’re only looking at that distributor’s inventory, and not all distributors offer this kind of tool on their websites. But if a preferred distributor offers this feature on their site, it's a simple way to locate out-of-stock parts, incorrect part numbers, back-ordered parts, and obsolete parts.

 

 

Electronic Component Search Engines

There are several component search engines that catalog supplier data across millions of part numbers. These search engines also include some BOM creation or parts list creation tools that can be used to spot out-of-stock parts. In our opinion, the best BOM scanning tool is found on Octopart.com, but there are others that will do the job.

With these tools, you upload a BOM, the tool scans through your part number list, and inventory data is pulled from their database. These services can also pull environmental information, life cycle status, and MOQs (Minimum Order Quantities) across distributors. Best of all, these supply chain tools are free to access and use.

 

 

Third-Party Logistics Platforms

Many third-party logistics platforms in use in the industry pull their data from component search engines, and they can be leveraged for a BOM review. The workflow is essentially the same as with a distributor website or a tool like Octopart. Just upload your exported BOM, and their system will scan through each part number and display the required supply chain information. These tools can also display electronic component information across vendors, and they will help with budgeting for a PCBA build.

 

 

Leverage Your PCB Design Tools

The best PCB design software will let you see supply chain data directly in the design tool. Free design software generally does not do this, and users are required to manually look up part number data to put in their libraries.

For example, Altium Designer includes an automated system that pulls supply chain information directly into the design tool and displays it in your PCB libraries. It will also pull this data into the schematics and into the bill of materials when creating outputs. To run a BOM review, just open up the BOM, look at the supply chain information, and you’ll be able to spot out-of-stock or expensive parts. Whenever a part doesn’t match supply chain data, that is your cue that the data listed in the library is incorrect and needs to be updated.

 

 

This access to supply chain information is one of the reasons we can streamline our design services for client projects. It eliminates a ton of extra work and headaches on the back end, and you’ll have the assurance that the project database you receive is complete and fully sourceable.

 

Whether you're designing high-speed PCBs for mil-aero embedded systems or a complex RF product, you should work with a design and development firm that can ensure your product will be reliable and manufacturable at scale. NWES helps aerospace OEMs, defense primes, and private companies in multiple industries design modern PCBs and create cutting-edge embedded technology, including power systems for high reliability applications and precision control systems. We've also partnered directly with EDA companies and advanced ITAR-compliant PCB manufacturers, and we'll make sure your design is fully manufacturable at scale. Contact NWES for a consultation.

 

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