Sourcing against the whole BOM
Most delays in a build start with one line item. A single connector on backorder, a capacitor at a distributor's minimum order quantity, a microcontroller with a twelve-week factory lead time — each one stops the whole order, and each one arrives from a different supplier with its own freight bill and its own packing.
Sourcing is therefore run against the whole bill of materials as one purchase: resistors, capacitors, diodes, transistors, amplifiers, ICs, connectors and the custom parts around them are bought together, kitted together and inspected together, then released to the line as a set. Parts can still be taken in stages when the production schedule calls for it.
Where the parts come from
Components are bought from original manufacturers and first-class franchised agents under a supplier certification system, with special chips and modules sourced worldwide when a part is not held locally. The common passives come from stock — more than 10,000 capacitor and resistor lines, including Yageo, Murata, AVX and Kemet — which covers the values a design change would otherwise wait weeks for.
Incoming material is inspected at IQC with professional test equipment before it reaches the assembly line, and moisture-sensitive devices are stored in temperature- and humidity-controlled chambers rather than left on a shelf in their reels.
Obsolete and hard-to-find parts
Once a part reaches end of life, the options narrow: buy remaining stock of the original part, find a pin-compatible equivalent, or redesign around it. All three are handled here — the part is located where stock exists, and where it cannot be bought, an alternative is proposed with the difference spelled out so the customer can approve the substitution, qualify it and update their documentation. Nothing is swapped silently on the line.
Mechanical parts with the electronics
Custom plastic, metal and cable assemblies are sourced with the electronic BOM, so an enclosure, a bracket or a wiring harness arrives with the boards rather than from a second supplier with a second lead time. That matters most on box build and turnkey orders, where the mechanical parts have to fit the assembled board.
When sourcing is the whole order
Sourcing is the right purchase when what is missing is material and nothing else: the boards are already specified, the line is already booked, and a backordered or unqualified part is what holds the schedule. From there the route splits by what the customer already holds.
A customer who has both the board supply and the assembly capacity arrives with a short list — a few long-lead-time parts, or one line item nobody can confirm — and buys only those, keeping the rest of the material in their own name. A customer whose part has reached end of life needs a decision rather than a purchase order, because the substitute has to be qualified and written into the documentation before any stock is booked. Where the bare boards themselves are still to be made, or the assembled boards still to be built, the purchase belongs to PCB manufacturing or to PCB assembly instead; where the finished unit is what is delivered — enclosure, harness, firmware, packaging — it belongs to box build.
Two boundaries decide whether a sourcing quotation can mean anything. The first is who carries the material risk: a brand or a channel named by the customer is bought exactly as named, with approval of any substitution left on the customer's side, while a part left open is bought on the supplier's judgement of what is available. The second is what "cheaper" is measured against — a part bought for immediate delivery and a part bought for traceability are rarely the same part from the same channel, so the priority has to be chosen before the search starts rather than after the prices come in.
How that material is then built is described under PCB assembly services.
Where the price of a part actually comes from
Two quotations for the same manufacturer part number can differ without either being wrong, because the part is not the only thing being bought. The first variable is the channel: an original manufacturer, an authorised distributor and an independent broker sell the same marking at different prices, and what changes with the price is traceability, returnability and the paperwork that comes with the reel. The second is quantity: the manufacturer's minimum packing, the price break above it and the annual volume behind it set the unit price far more than the component's complexity does, which is why a single small order carries costs that a running volume has already absorbed.
Time is the third: a part bought from stock is paid for at today's price for the convenience of delivery, while a part bought against a factory lead time is paid for at a price agreed today and delivered into a market that may since have moved. Who carries that window — and who carries the allocation if the part goes short — has to be written down, because it is otherwise discovered at the delivery date.
Replacement carries its own cost, which the alternative part's price never shows: confirming the equivalence, qualifying it, updating the bill of materials and the customer's documentation. Incoming inspection and traceability work the same way — the depth of the check and the batch record are part of what is being bought, and a cheaper channel usually hands that work downstream instead.
Two quotations are therefore only comparable on the same bill-of-materials revision, the same channel, the same quantity basis and the same delivery terms; otherwise the difference in price is measuring a difference in scope. The inspection behind the batch record is described under PCBA testing and quality assurance.
One quotation, one delivery
Send the bill of materials with manufacturer part numbers and the annual or per-order quantities. Sample quantities come through in seven working days and mass-production quantities in two to three weeks, and the BOM quotation is issued within 24 hours. Where a design is still being defined, the prototype service can build a small batch from the same BOM first, and the capability page lists the process limits involved.
