Sourcing a Full Aerospace Bill of Materials
BOM sourcing means handing one partner your whole parts list, with machined parts, sheet metal, hardware, seals, connectors, EEE parts and raw material on it, and getting back one quote, one purchase order and one certificate of conformance package. Aerospace Sourcing splits the list by supplier type, flows down your requirements line by line, checks the paperwork and brings it back together for delivery.
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What BOM sourcing covers
It covers any list where the lines would normally go to several different kinds of supplier. A typical aerospace build sheet mixes made-to-print parts, catalog hardware bought to a military or industry standard, electronic components with their own counterfeit rules, and stock material cut to size. Buying each of those yourself means a separate quote, PO, receiving inspection and paperwork file for every supplier.
Common examples we see described by buyers:
- A ground support equipment build where frames, brackets and panels are fabricated, and the fittings, hoses, valves and fasteners are bought
- A test fixture or flight-like engineering unit with machined housings, connectors, harness parts and a short list of ICs and passives
- A spares order for an older system that mixes current catalog items with a few obsolete line items
- A material and hardware list for an in-house assembly line, where the buyer wants everything kitted by assembly
The value is not in any single line. It is in having one party responsible for the whole list: one place to ask about status, one set of flow-downs, and one paperwork package your receiving inspector can check against the BOM.
How a mixed BOM gets split
Each line goes to the kind of source that can supply it with the right paperwork, and the paperwork that comes back differs by line type. The split below is how the work is normally organized.
| Line type | Typical source | Paperwork that should come back |
|---|---|---|
| Machined parts to your drawing | Machine shop, plus outside processors for finish, heat treat or NDT | Material certs, process certs, FAI when required, CoC |
| Sheet metal and welded parts | Fabrication shop, plus welding and finishing processors | Material certs, weld and process certs, CoC |
| Standard hardware (fasteners, washers, pins, inserts) | Manufacturer or an authorized distributor | Manufacturer CoC with lot number, distributor CoC |
| Seals, O-rings, sealants, adhesives | Manufacturer or authorized distributor | CoC with batch and cure or manufacture date for shelf life items |
| Connectors, contacts, wire | Manufacturer or authorized distributor | CoC with lot or date code, QPL source where the spec has one |
| EEE parts (ICs, discretes, passives) | Original manufacturer or its authorized distribution first | Manufacturer and distributor CoC, date and lot codes, test reports if an independent source is approved |
| Raw material (bar, plate, sheet, tube) | Mill, metals service center, or certified surplus | Mill test report traceable to heat or lot, specialty metals compliance where required |
Where one line feeds another, such as material that a machine shop will cut, the material is either bought by the shop under your flow-downs or supplied to it with its certs. Either way the heat or lot traces from the mill report to the finished part.
Have a part like this?Send it in under a minute. A person replies within 1 business day.What to put in the BOM you send
Send the BOM as a spreadsheet with one row per unique part and these columns filled in. Missing columns are the most common reason a BOM quote comes back with questions instead of prices.
- Part number and revision for every line, exactly as on the drawing or parts list, including dash numbers and finish codes
- Description in plain words, so a mistyped part number can be caught
- Quantity per assembly and total quantity, with the unit of measure (each, feet, pounds, kits)
- Make or buy: whether the line is built to your drawing or bought as a standard or catalog item
- Governing spec for standard parts (NAS, MS, AN, AS, or a military specification) and for material (the AMS, ASTM or military spec and temper)
- Approved manufacturers from your approved vendor or approved manufacturer list, and whether the list is closed or open
- Approved alternates already released by your engineering
- Reference designators for electronic parts, so a question about one position does not stall the whole line
- Need dates, per line if some parts are needed before others
- Export classification for any line or drawing that carries one
Attach the drawings for every make line at the revision listed. If a drawing is newer than the BOM, say which one governs. Our aerospace RFQ checklist covers the drawing side of the package in more detail.
Approved vendor lists, approved manufacturers and alternates
If your BOM names approved manufacturers, only those manufacturers are quoted for the line. An approved vendor list (AVL) usually controls who you may buy from, while an approved manufacturer list (AML) controls whose product may be installed. Many programs use one term for both, so say which one you mean.
Three situations come up often:
- Single approved source. The line can only come from one manufacturer. It is quoted from that manufacturer or its authorized distribution, even when a cheaper equivalent exists.
- Several approved sources. Any listed source can be quoted. If you want a preference, put it in the BOM.
- Spec controlled with a qualified products list. Some military specifications have a QPL or QPD of approved sources. For those lines, the part should come from a listed source, and the CoC should show it.
A line with no approved source listed is quoted to the governing spec only. If that is not your intent, list the sources.
Long-lead items
Long-lead lines are flagged with the quote so you can decide early whether to release them ahead of the rest of the order. Lead time on a BOM is set by its slowest line, and it is often a single forging, a specialty connector, a mil-spec relay or a part made to order by the manufacturer.
Ways buyers deal with them:
- Release the long-lead lines first on a separate line item or PO revision, then release the balance once the drawings are final
- Accept partial shipments, so the parts you need first are not held for the slowest line
- Ask whether an approved alternate, a different package or a different finish on the same spec is available sooner, and route that through your engineering for approval
- For raw material, ask whether certified surplus in the right spec and temper would work, with full mill certs
We report the quoted lead time for each line and the date that drives the order. We do not promise a lead time we cannot get from the source. The lead times and delivery guide explains what drives lead time by part type.
Obsolete line items
An obsolete line is searched separately so it does not hold up the rest of the BOM. Usually it is one or two parts on an older design: a discontinued IC, a connector variant no longer built, or a fastener to a cancelled standard.
The first step is to confirm the status with the manufacturer and look for a released replacement. If there is none, the search follows the same order of risk described on our obsolete aerospace parts page: the manufacturer and its authorized distributors first, then independent distributors only with your approval, traceability and testing to the standard you require, then a remake from drawings where the part is mechanical.
For electronic lines on defense work, DFARS 252.246-7008 sets out a preference for buying from the original manufacturer and its authorized suppliers, with added steps when that is not possible. Our counterfeit parts avoidance page explains those steps and the SAE standards behind them.
Substitutes that need your approval
No substitute goes on your order without written approval from you, and from the design authority if your contract requires it. That rule applies even when a substitute looks identical on a data sheet.
When a line cannot be supplied as written, you get a substitution request that shows:
- The BOM line, the original part number and revision, and why it cannot be supplied (obsolete, no stock at any approved source, minimum buy, lead time)
- The proposed part number, manufacturer and governing spec
- A side by side of the characteristics that matter for that part type: dimensions, material, finish, ratings, temperature range, qualification level and screening
- The data sheets or spec pages behind the comparison
Your engineering decides. Some changes look small but are not: a different plating on a fastener can change galvanic behavior and torque, a commercial grade part may not meet the screening your program assumed, and a seal compound change can affect fluid compatibility. The approved substitute and the approval reference are recorded on the line so the cert package shows what was actually delivered.
Bringing the BOM back together
Every line is checked against the BOM and its paperwork before the order ships as one delivery or in the partial shipments you agreed to. The check covers part number and revision, quantity, manufacturer against your approved list, lot or date codes, and the certs each line needs.
You can ask for the parts to come back in the form that suits your receiving and assembly:
- By BOM line, each bag or box labeled with the line number, part number and quantity
- By assembly or kit, if you build several assemblies from one BOM. Our aerospace kitting page covers kit definitions, labeling and lot traceability inside kits.
- With electrostatic discharge sensitive parts kept in ESD protective packaging and marked as such
- With shelf life items labeled with their cure or expiry dates
One certificate of conformance package
The order ships with one certificate of conformance package indexed to your BOM, so your inspector does not have to match loose papers to lines. The package normally includes:
- A certificate of conformance for the order, listing each BOM line, part number, revision and quantity
- The manufacturer or distributor CoC for each bought line, with lot or date codes
- Mill test reports for raw material and for material used in made parts, traceable to heat or lot
- Process certs for finishing, heat treat, NDT or welding on made parts
- First article inspection reports where your PO calls for them, in the AS9102 format if required
- Records of any approved substitutes, with your approval reference
- Test or inspection reports for any line bought from an independent source with your approval
Our certificate of conformance page explains what a CoC should state, and the material certs and traceability guide covers mill reports.
Revision changes after the order is placed
A BOM revision after release is handled as a change to the order, line by line. Send the new BOM with the changes marked, and you get back which lines are affected, which have already shipped or started, and what the change does to cost and date. Lines already built to the old revision are not reworked or scrapped without your direction. This is also why the BOM revision should appear on the PO: it fixes which list the order was placed against.
Export control and controlled data in a BOM
A parts list can carry export controlled or CUI drawings even when most lines are catalog items. Do not upload controlled drawings through the website. Tell us the program is controlled, and the data moves by secure transfer to US persons only. Each supplier signs a flow-down NDA before it sees your files, and suppliers do not learn who the end customer is unless you approve it. Our confidentiality page and controlled programs page describe how that works.
For defense programs, also say whether DFARS specialty metals rules apply, because they affect the material and fastener lines. Our DFARS specialty metals page covers what that clause requires.
Where the parts lines come from
Bought lines are sourced through the manufacturer or its authorized and franchised distribution, with lot traceability and the manufacturer CoC. We do not hold inventory and do not quote from a catalog of our own. The parts guide explains what governs each family and what to put on the PO, including fasteners, seals and fluid parts, connectors and wire, electronic components and raw material.
How Aerospace Sourcing handles a BOM
We are a sourcing service. We do not run machines or stock parts. We take the whole list, split it among qualified suppliers and sources, and manage it through delivery.
- One quote, one lead time, one point of contact and one purchase order, even when many suppliers are behind the lines
- Your requirements flowed down line by line: approved sources, specs, FAI, traceability, special processes and specialty metals
- Obsolete and long-lead lines flagged early, and every substitute sent to you for written approval
- Paperwork checked against the BOM before shipment
- A certificate of conformance with every order, plus the certs your request requires
Send your BOM for a quote
Upload the BOM spreadsheet and the drawings for the make lines through the BOM quote request, and note any approved manufacturer lists, alternates and need dates. A complete list lets us flag long-lead, obsolete and single-source lines in the first reply instead of after the order. A person replies within one business day. If any drawing is export controlled, say so on the form and leave the file off.
Send the job. A person replies within 1 business day.
Part, quantity and date are enough to start. Drawings and the mutual NDA follow by reply, and controlled programs never send technical data through this site.
We have it.
Reference . A person replies within 1 business day. Watch for our email from [email protected].
Questions
Can I send a BOM with only some lines I want quoted?
Yes. Mark the lines you want quoted and leave the rest in the file for context, or delete them. Seeing the full list can still help, because it shows how parts relate, which lines feed an assembly and whether a material line is meant for a machined part. You get one quote for the lines you selected, with a quoted lead time for each line and the line that drives the overall date.
Will you substitute a part if the one on my BOM is not available?
Not without your written approval. If a line cannot be supplied as written, you get a substitution request showing the original part, the proposed part, the reason, and a side by side of the characteristics that matter, with data sheets attached. Your engineering, and the design authority where the contract requires it, decides. Approved substitutes are recorded in the cert package so the delivered configuration is documented.
What is the difference between an AVL and an AML?
An approved vendor list usually names the companies you may buy from, such as specific distributors or shops. An approved manufacturer list names whose product may be installed in your hardware. A part can come from an approved vendor but still need to be made by an approved manufacturer. Programs use the terms loosely, so state in your BOM which list applies to each line and whether it is closed to other sources.
Can electronic parts on my BOM come from independent distributors?
Only if you approve it. The default is the original manufacturer or its authorized distribution. For defense work, DFARS 252.246-7008 sets a preference for those sources and adds requirements when they cannot supply the part. If an independent source is the only option for an obsolete line, you decide whether to accept it and what testing and traceability to require, typically to an SAE standard such as AS6081 or AS6171.
Do I get one certificate of conformance or one per part?
Both, organized as one package. The order carries a certificate of conformance listing every BOM line, and behind it sit the manufacturer and distributor CoCs, mill test reports, process certs and any FAI reports for the individual lines. The package is indexed to your BOM line numbers so your receiving inspector can check each line without matching loose papers by hand.
How do you handle a BOM revision after the order is placed?
Send the revised BOM with the changes marked. You get back a list of affected lines, which ones have shipped or started, and the effect on cost and date. Nothing already built to the old revision is reworked or scrapped without your direction. Putting the BOM revision on the purchase order fixes which list the order was placed against, which keeps the change clean.
Can you deliver the BOM as kits instead of loose lines?
Yes. Tell us how the kits are defined, usually by assembly, work order or installation, and how each bag should be labeled. Kitted parts keep their lot traceability, shelf life items carry their dates, and ESD sensitive parts stay in protective packaging. The kitting page explains what buyers usually specify for kit content, labels and documentation.
Related
Sources
- Acquisition.gov: DFARS 252.246-7008 Sources of Electronic Parts
- DLA: SAE counterfeit standards overview (AS5553, AS6174, AS6081, AS6496, AS6171)
- Cornell LII: DFARS 252.225-7009 Restriction on acquisition of certain articles containing specialty metals
- TUV NORD: AS9120 quality management for aerospace distributors
- ESD Association: An overview of ANSI/ESD S20.20
- EverySpec: MIL-STD-31000B Technical Data Packages
- ANSI Webstore: SAE AS9102C First Article Inspection Requirements
- NQA: AS9100:2016 (Revision D) published
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