I'm wondering, if one of those custom parts doesn't work as intended due to a mistake on the provider's part. Do you get another fixed one in a shorter period of time or the 10-12 weeks are valid no matter what?
Outside of metal we've rarely had any problems with the quality of parts. The 10 - 12 week lead time is simply the time it takes for the part to be scheduled and built. We simply take that in to account and proceed accordingly. To get the best pricing on components, we need to schedule our purchases months in advance. Purchasing from Mouser and Digikey is okay in a pinch but there is a risk they won't have the part you need and you will pay an additional 20 - 30% or more over a scheduled delivery. 10-12 weeks is an estimate however, and there can be delays.
Our biggest debacle with delayed parts was last year when we getting set up to do our second Yggdrasil run. I had placed an order for the Analog Devices AD5791 chip through [a major parts house]. This is a pretty expensive chip. About a week before delivery I get an email from [a major parts house] and Analog was going to be a month late with their delivery. I needed to find 1000 AD5791 chips. At the time, this chip was very hard to locate and I couldn't find 1000 of them anywhere.
In working with electronic parts, I've worked with four kinds of suppliers/distributors. The big distributors are companies like AVNET and Future. They purchase direct from the manufacturer, have huge line cards with tons of different suppliers, have tons of people, but I have found the service to be poor and they are generally indifferent to problems that we have experienced.
The small distributors have smaller line cards, the service is a lot more personal, and they will go out of their way to take care of you. Relationships are a lot more important at that level. I prefer to purchase from these types of distributors. Prices are generally about the same as the big guys- but you need to order in advance of your need because they don't have the capital to stock a massive warehouse with parts you may or may not need. These guys will work their butts off to keep you as a customer.
Next, you have the big stock houses that keep tons of stock available for purchase online. These are the Mousers and Digikeys. They usually have the part or something close to it. You will pay a price premium for this convenience. They have fast shipping. We used to use these guys as our main suppliers. Now, we only use them for fill-in and emergency orders. There is little relationship and no loyalty with these guys. I have spent millions of dollars at Mouser since 2012. When I call, they treat me the same as if I was the guy spending $45 on a DIY project. They've never called and asked me if I needed anything. They've never offered a price break beyond what is listed on the website. They've never gone out of their way to help with a back order.
Finally, the bottom-feeders. These are the guys who are the trolls. They buy up hard to find parts, wait for a shortage, and then sell them at inflated prices.
Back to last year, I found a bottom-feeder who had 1000 pcs of the AD5791. He would sell them to me, but the price was about 25% more than I would have paid at [a major parts house]. This was a price is no object moment. Yggy was red-hot and we had sold out of the first run in less than 30 days. So I sent over a PO, filled our the Net30 credit application and went with it. First they quoted 3 days- wonderful. Then the confirmation said seven days. Okay, I can live with that. They charged a huge chunk of the cost to my AMEX as a surety. 7 days came and went. I called.
"Where are my parts?"
"They need to test them, and then we'll get them over."
This guy was playing me. Microchips are shipped in sealed, vacuum packed, moisture free bags. No one opens those things outside of a production environment. One shock and an $80 microchip is worthless.
"No one tests microchips- when will they get here?"
"A few more days."
So I went back to waiting. May flowed in to June. No parts. I called. I emailed.
Each time, it was a different story. Shipping delays. Problem in the warehouse. I was being strung along, at that moment, I didn't have a choice. [A major parts house] had bumped my April shipment back again, so there was no relief coming from my original supplier.
I threatened to pull the order and do a chargeback if the parts weren't shipped. They finally shipped 26 days after the quoted time period. What were they doing during that time? My guess is they were buying them up from other suppliers that I didn't have access to and then reshipping them to me. The guy just needed to keep me on the hook until that happened. The backordered Yggys were shipped in July, right before the launch of the Gungnir Multi. I guess I should be thankful he didn't ship me counterfeit parts.
The company called me weeks later trolling for business. I told them I wouldn't buy a fire extinguisher from them if my ass was on fire and to never call me again. I guess my comment got back to the salesman I worked with. He called and tried to mend fences. I'll never get those four minutes back.
I learned to schedule parts, to order early, and to keep a buffer.