A BOM scrub is the pass that turns a design document into a purchasable one. Most BOMs that reach a sourcing desk are technically correct and commercially unusable: a manufacturer name with no orderable part number, a package column that names a footprint instead of a shipping format, a resistor line that has been obsolete since 2019. Nine checks catch almost all of it, and the scrub below runs those nine against one real 14-line control board so you can see what each pass actually returns.
What a BOM scrub is, and what it is not
A BOM scrub validates and completes every line of a bill of materials until each one is a single orderable part number with a quantity, a lifecycle status and a known availability. It is a data and risk pass, not a cost-reduction exercise and not a design review. Nothing about the circuit changes. What changes is that a buyer can now price it, an EMS can quote it, and an ERP can raise a purchase order from it without sending questions back.
The distinction that trips people up: a scrub is not the same as a BOM evaluation. The scrub makes the BOM orderable. An evaluation takes an already-clean BOM and looks for cost, risk and alternate-sourcing options across it. Scrub first, evaluate second. Our BOM evaluation guide covers the second step; this post is the first.
The nine checks, in the order that saves the most time
Run the checks in this order, because each one shrinks the work in the next. Deduplicating 14 lines down to 12 before you start lifecycle lookups saves two lookups; doing it afterwards wastes them.
| # | Check | What it catches | Line is clean when |
|---|---|---|---|
| 1 | Structure | Merged cells, missing reference designators, quantity that does not match the designator count | Qty equals the number of RefDes on that line |
| 2 | Deduplication | The same part entered twice under two internal numbers | One row per manufacturer part number |
| 3 | MPN validity | Base numbers, truncated numbers, description-only lines | The number resolves to one orderable device at the manufacturer |
| 4 | Manufacturer match | Part number and brand that belong to different companies, or a brand that has since been acquired | MPN and manufacturer agree on the manufacturer's own site |
| 5 | Lifecycle | NRND, EOL, last-time-buy and obsolete lines | Status is recorded with the date you checked it |
| 6 | Availability | Lines with no stock anywhere, or lead time past your build date | Stock or lead time is written on the line |
| 7 | Packaging and format | Reel, cut tape, tube and tray confusion; MSL handling | Shipping format is stated, not implied by the footprint |
| 8 | Compliance | Missing RoHS, REACH or exemption status on the exact orderable code | Compliance is tied to the suffix, not the base number |
| 9 | Alternates | Single-source lines with no approved backup | Critical lines carry a named, engineering-approved alternate |
Checks 1 to 4 are data hygiene and can be done by anyone with the manufacturer sites open. Checks 5 to 9 are sourcing judgement and are where a scrub either earns its keep or quietly fails.
Scrubbing one 14-line BOM: what each pass found
The board is a small industrial RS-485 control module: one 16-bit MCU, one transceiver, a regulator, passives, two connectors. Fourteen lines went in. Here is what came back out of each pass.
Passes 1 and 2 (structure, deduplication) removed two lines. Two 100 nF 0603 capacitors were listed separately because they carried different internal part numbers from two different projects. Same manufacturer, same MPN, merged into one line of 18 pieces. A third line had a quantity of 4 against six reference designators, which is the single most common structural error and the one that shows up as a shortage on the line, not in the spreadsheet.
Pass 3 (MPN validity) rejected the line that matters most. The transceiver was entered as "SN75176B, RS-485, SOIC". That is not an orderable part. Texas Instruments lists the SN75176B with three package suffixes - D for SOIC-8, PS for SOP-8 and P for PDIP-8 - and the base number by itself selects none of them (see the TI product page for SN75176B, which also confirms the device is still ACTIVE, not obsolete). Add tape-and-reel and the suffix grows again: DR rather than D. Add TI's Pb-free green designator and it becomes SN75176BDRG4.
That resolved code is a real line we can price: GlobX holds 6,000 pieces of SN75176BDRG4, ready to ship from Germany. The unresolved version, "SN75176B, SOIC", would have come back from three distributors with three different answers, one of them in tubes. If suffix decoding is the check your BOMs keep failing, our part number suffix decoder maps the ordering codes for seven chipmakers side by side.
Pass 5 (lifecycle) flagged the MCU. The controller is an Infineon C167 family device - a 16-bit architecture that is long past its design-in window but still runs in a large installed base of industrial and automotive equipment. On a new design that flag means redesign. On a repair or a last-build run it means buy the window while it exists: GlobX shows 3,500 pieces of C167CRLMHAKXQLA2 with 21+ date codes, in Germany. Record the status with the date you checked it, because lifecycle is the one BOM attribute that changes without anybody telling you. A line marked NRND is not yet a problem but is a scheduled one, which is why NRND parts need a decision before the next build, not after it.
Pass 6 (availability) moved the build date by five weeks. Two lines were quotable but not in time. As of September 2026, microcontrollers are widely quoted at 30 to 55 weeks and memory at 26 weeks or more, so a scrub that stops at "this part exists" tells you nothing about whether you can build in Q1. Availability belongs on the line as a number. Our 2026 lead time guide gives the current figures by category.
Pass 7 (packaging) caught a cost, not a shortage. The 18-piece capacitor line had no shipping format. At 18 pieces you want cut tape; at 3,000 you want a full reel, and a reel of the wrong 0603 is money parked on a shelf. The tape and reel versus cut tape comparison sets the break points. Moisture-sensitive lines need the same treatment: an MSL rating on the line tells your assembler whether the part needs baking before it goes near a reflow oven.
Pass 8 (compliance) found one gap that the base number hid. RoHS status attaches to the orderable code, not the family. Legacy stock with older date codes may sit under an Annex III exemption whose expiry has since moved - several lead exemptions changed during 2026, and the date that counts is the day you place the product on the market.
Pass 9 (alternates) left three lines single-sourced on purpose. Not every line needs a backup. The connectors and the MCU do, because a stop there stops the build. The 0603 passives do not, because they are fungible across four manufacturers at the same price. Naming an alternate on every line is the fastest way to make a scrub look thorough and be useless.
Where scrubbed BOMs still go wrong
The failure mode is not a missed check, it is an undated one. A BOM scrubbed in March and quoted in September carries lifecycle and availability data that has silently expired, and it will quote cleanly right up until the purchase order bounces. Put a check date in the sheet, per line, not a version number on the file.
The second failure mode is scrubbing without recording what you decided. If pass 9 concluded that three lines stay single-sourced, write that down. Otherwise the next buyer repeats the analysis, or worse, quietly substitutes a part that was rejected for a reason nobody captured. Where a line genuinely needs a backup, second sourcing has to be set up before the shortage, not during it.
What a scrubbed BOM should contain when you send it out
A quote-ready BOM carries eleven columns, and a distributor that gets all eleven can return a firm price without a single clarification email. Line number, reference designators, quantity per board, internal part number, manufacturer, manufacturer part number in full orderable form, description, shipping format, lifecycle status with check date, approved alternate where one exists, and any compliance requirement that applies to that line.
Ask for the same discipline back. A useful quote states exceptions, lines the supplier could not offer, any proposed alternate with its MPN, minimum order quantities, lead time per line, and the packaging each price assumes. Trade bodies track the supply-side half of this: ECIA's monthly Industry Pulse survey reports decommits, cancellations and lead-time trends across the authorised channel, which is a reasonable sanity check on whether the lead times you are being quoted match the market.
How long a scrub takes, and when to hand it over
A 14-line BOM takes 30 to 45 minutes by hand. Scaling is not linear: 200 lines takes most of a day, because lifecycle and availability lookups dominate and cannot be batched reliably across manufacturers. Below roughly 50 lines, doing it yourself is faster than briefing anyone. Above 150 lines, or when more than a tenth of the lines come back NRND, EOL or on allocation, the lookups stop being the hard part and the sourcing judgement starts being the hard part.
That is the point to hand it over. Send us the BOM in whatever state it is in - GlobX will return the scrubbed version with lifecycle status, live European stock and named alternates on the risky lines, and quote the lines you want covered. Messy spreadsheets are expected; that is what the pass is for.
