Research firm Blancco has published a Mobile Device Repair and Security Report that threw up some interesting facts. The report puts Samsung as the OEM with the highest failure rate among Android manufacturers and the Xiaomi Redmi 4 as the specific model with the highest failures in 2017. In the Apple camp, the iPhone 6 was the device with the highest failure rate.
https://www.notebookcheck.net/Report-Xiaomi-Redmi-4-and-Apple-iPhone-6-were-the-worst-performing-smartphones-of-2017.316624.0.html