BOM Fatigue

Member
Joined 2019
Paid Member
It's your next project, you bought the boards, you can't wait to get stuffing, but there are components you've got to order.
  1. It's almost certain that no supplier will have all the components in stock
  2. There will be at least one vital component that's got a resupply date more than a year away
  3. For components in #2, there are people on EBay who, apparently, have loads for sale. But you just know they're going to be fakes. Or are they genuine???
  4. A minimum of two suppliers will be needed and, for at least one of those suppliers, the order value will be far exceeded by delivery charges
  5. Suppliers in #4 will not have anything else you want to order to exceed the free delivery minimum
  6. In the rare situation where a supplier has everything in stock there will always be at least one component at such a high price you resent paying for it.
  7. All #6 items are available from other suppliers and at much lower prices *and* in stock. But they can't supply all of your BOM and you're back at #4
  8. For #2, there are other components that appear to be compatible and are available. But are they *really* compatible? The BOM specifies a 65v dc capacitor that's unavailable, but there's a 35v version that looks ok. But is it? It's only a 15v phono pre so, really it's gotta be OK. But the designer must have chosen the 65v version for a reason. Right? Right??
  9. The calculations to get the optimum overall spend balancing order cost, delivery cost, and delivery date is so complex you begin to wonder why you're bothering
  10. Once you have done the calculations for an optimum order you find one supplier doesn't ship to where you live [mbrennwa ]
  11. No matter how hard you try, you'll forget to order one component and you won't discover you don't have it until you're stuffing the board and you'll pay way over the odds to get it quickly.
Or at least that's been my experience to date.
 
Last edited:
do-not-pass-go-do-not-collect-two-hundred-dollars.jpg
 
So job is knackered.


Digi and mouser both have stock depending on which variant you want.


When RS don't actually spec the incoming date I've found it's because they've effectively stopped selling it, but it keeps the tally of parts they stock up in the mean time.... I've forgotton how many times I've ordered stuff with no date at all and that 'we'll ship when stock is available' message and eventually you get a no longer stocked email
 
Last edited:
The last time I looked at the Trenz Electronic website, almost all their FPGA modules were out of stock and there was a big warning about long lead times (order of 52 weeks) on their site. I just looked again and now they also have a warning about fake webshops. A few months ago, one forum member on the valve DAC thread managed to buy the complete world stock of the Trenz TE0630 LX75 modules, that is, both of them.
 
Administrator
Joined 2004
Paid Member
1 - 10 in general, but in particular 11. Just lived through that conundrum, and then I had to order it again because the USPS tracker told me it was lost - only to have it show up 3 days before the parts I ordered to replace it.. LOL

Thank you for the great opening post, it made me smile and little does these days. Things sort of suck here a bit at the moment.. :D
 
Yup, it must be frustrating. But most of that top 10 list seems familiar, I mean one way or another these challenges were popping up for years before the current parts shortages made it all worse.

My solution ? I’m building a set of chassis for amps instead of chasing various parts. And so it means I’ll have a stack of metalwork done which will serve me well for amp building over the next year or so as things ease. I’m also refurbishing some speakers with some woodwork and drivers etc.

All in all, there are enough things to keep me busy catching up on projects that don’t need parts.

And I’ll add

12. One of the small parts will ping out of your hands/tweezers/packaging and permanently disappear into the carpet, now you’re a part short.
 
Last edited:
In 40 years as a design engineer, I never saw component shortages like this.

4 years ago capacitor shortages were manageable.

The shortage of ICs years ago due to a plastics manufacturer fire that depleted 50% of the encapsulation plastic world wide was a drop in a bucket compared to this.

Seeing Covid in the rear view mirror can't come too soon.