I'm going to challenge you on "...can't be fixed on just one end of the process" Why not? That seems like the appropriate place to reject the inferior componen

I'm going to challenge you on "...can't be fixed on just one end of the process" Why not? That seems like the appropriate place to reject the inferior components arriving from that long and deep supply chain. You're creating a soap dispenser for sale in North America. It does not work on 15% of the population. That's a fail. You can't just throw your hands up and say, "Well, those photoreceptors were designed in Taiwan, and they didn't account for dark skin". If that's the case then you don't source those, or you request a different calibration profile, or you add a lens filter that compensate. You engineer the solution for your target market. The same company using global components took the time to print logos in English and the user manual in English. They made sure the power circuitry matched North America's system. They set up a domestic phone number for support. Established payment systems to accept USD for their product. They do all these things to sell better into a particular market, but they don't bother with the actual people who will be using it? Don't get me wrong. You are accurately explaining the how of the failure. But that's exactly why the last step in the supply-chain exists. To make the actual finished product. That's where you catch deficiencies like this.