If you supply your own components to your contract manufacturer, the current shortage lands on your desk before it lands on ours. In consigned kitting for electronics manufacturing, you buy the parts, you own the availability risk, and you can only start building when the last reel arrives. This post is for customers who kit parts to Thomas Instrumentation, and for anyone else running a customer-supplied kit model. It covers which lines on a kit BOM are actually at risk, how far ahead to buy, what to hold versus bond, and what to tell us so shortfalls show up at quote time instead of at kit receipt.
The Short Version of What’s Happening
AI data centers have pulled memory, capacitors and other components out of the general market, and prices and lead times have followed. For the full picture, start with our explanation of chipflation. Everything below assumes that background.
Turnkey vs. Consigned PCB Assembly: Where the Risk Sits
In a turnkey build, your contract manufacturer sources every part, so allocation, lead times and substitutions are the manufacturer’s problem to manage. In a consigned build, you supply some or all of the parts, and those decisions are yours. Many customers run a mix, supplying high-value or customer-specific parts themselves and letting the manufacturer buy the rest.
There are good reasons to kit. You may have negotiated pricing, existing inventory, or parts that only you can buy. None of that changes during a shortage. What changes is how early you need to act, because a consigned kit that arrives short stops the line just as surely as a turnkey part that never shipped.
Which Lines on a Kit BOM Are Actually at Risk
Most lines on a typical BOM are still fine. The ones that aren’t tend to fall into a few groups:
- Memory. DDR4, LPDDR4, DDR5, NAND, eMMC and NOR flash. DDR4 and LPDDR4 are under allocation, and DRAM lead times are running 26 weeks or more.
- General-purpose MLCCs. Especially values in the 1µF to 22µF range, where channel inventory has dropped sharply. These are cheap parts that can stop an expensive build.
- High-capacitance and high-voltage MLCCs. Common in power stages. Some are quoting around 40 weeks at distribution.
- Aluminum electrolytic, polymer and tantalum capacitors. All included in this year’s broad supplier price increases.
- Microcontrollers, processors and programmable logic. Lead times on some programmable logic are approaching 52 weeks.
- Anything single-source, NRND or end-of-life. A part with one manufacturer and no approved alternate is a risk in any market. In this one, it’s the first thing to check.
The mistake we see most often is focusing on expensive parts. The part that holds up a kit can just as easily be a capacitor that costs a fraction of a cent.
When to Buy Ahead of a Component Shortage
Work backward from the build date. For each at-risk line, add together the supplier’s current lead time, the time for the parts to reach you and then us, receiving inspection, kit preparation, and a buffer for the delivery slipping. That total is how far ahead of the build you need to place the order.
For lines with memory quoting 26 weeks or longer, that math means a build in the second quarter of 2027 needs its memory ordered now. For lines quoting 40 or 52 weeks, you may already be late for the first half of next year.
If a part is going away entirely, the question changes from “how far ahead” to “how much, for how long.” That’s a different decision, and we’ve laid out the options in our guide to last-time buys, redesigns and new designs.
A Safety Stock Strategy for Electronic Components
Safety stock is the buffer you keep on top of what a build needs, to absorb late deliveries and short shipments. It shouldn’t be applied evenly across the BOM. Put it where the risk is:
- Size safety stock by lead-time variability, not by unit cost. A part whose delivery dates have been slipping needs more buffer than an expensive part that always arrives on time.
- Cover at-risk lines for at least one full build beyond the current one, so a single late shipment doesn’t become a missed delivery.
- Review the buffer every quarter. Lead times are moving, and a buffer set in the spring may be too thin by the fall.
What to Hold Versus What to Bond
Holding means you own the inventory and store it, either at your site or with us. Bonding means a distributor or supplier keeps stock reserved for you under an agreement and releases it on a schedule.
Hold the lines with allocation risk, long lead times, volatile pricing, or end-of-life dates. These are the parts where physical possession matters, because a bonded commitment during allocation is only as good as the supplier’s ability to honor it. Bond the higher-volume, steadier lines where a distributor is willing to commit, which keeps your cash and storage free for the parts that need it.
Whatever you hold has to be stored correctly. Moisture-sensitive devices need dry storage and tracked floor life under IPC/JEDEC J-STD-033, and parts left in the wrong conditions can fail at reflow. Our production floor uses climate-controlled component storage towers, so parts stay in proper condition between receipt and build.
What to Tell Us at Quote Time
This is the section to share with whoever manages your kits. The more of this we see when we quote, the more problems we can catch before the kit ships:
- The full BOM with manufacturer part numbers and approved alternates. Alternates you’ve already approved give us room to move if a line comes up short.
- Which lines you’ll supply and which you want us to source. Be specific, line by line.
- What you have on hand and on order, with confirmed dates. Confirmed dates, not expected ones.
- Any allocation or end-of-life notices you’ve received. Forward them. They’re often the earliest warning either of us gets.
- Your build schedule and a 12-month forecast. Firm quantities get served first in a tight market.
- Packaging details. Full reels, cut tape or trays affect how parts load on the line and how much attrition to plan for.
With that information, a shortfall becomes a line on the quote we can talk through, instead of a phone call the week the kit arrives.
Kit Problems Are Usually Visible Months Earlier
When a kit arrives short, the cause is almost always something that could have been seen much sooner: a lead time that quietly stretched, an allocation notice that didn’t reach the right person, or a PO that was placed against an old quote. None of these are hard to catch. They just require someone to look before it’s too late to act.
That’s the part of our electronics manufacturing services that matters most right now. We review consigned BOMs against what we’re seeing in the market, and we’ll tell you when a line looks at risk even if you’re the one buying it.
Frequently Asked Questions About Consigned Kitting
What is consigned kitting in electronics manufacturing?
Consigned kitting is an arrangement where the customer buys and supplies some or all of the components for a build, and the contract manufacturer assembles them. The customer controls part sourcing and pricing, and also carries the availability risk.
Is turnkey or consigned PCB assembly better during a shortage?
Neither is automatically better. Turnkey shifts sourcing work to the manufacturer, while consigned lets you use your own pricing and inventory. During a shortage, many customers move specific at-risk lines to turnkey while keeping the rest consigned.
How much safety stock should I keep for electronic components?
Base it on lead-time variability and the cost of a missed build rather than on part price. For lines with allocation risk, covering at least one full build beyond the current one is a reasonable starting point.
Can Thomas Instrumentation source some lines while I supply the rest?
Yes. Mixed kits are common, and we’ll quote the lines you want us to buy alongside the ones you supply, so the full kit is covered.
Someone Should Be Watching Your BOM
Our customers hear about problems like these early because someone here is actually watching their BOM. If you kit parts to us, send your current BOM and build schedule, and we’ll tell you which lines we’d act on first. Contact our team to set up a review before your next kit ships.
