We are also assuming that the article is worded correctly. It could very well mean that the assembly time for 1 unit is 30 seconds total from start to finish, and the wording is just inaccurate. It happens a lot with articles like this, so who knows.

EDIT: another commenter points out that another version of the article does indeed say 30 seconds to complete one unit, as opposed to “one unit per 30 seconds”

>another commenter points out that another version of the article does indeed say 30 seconds to complete one unit, as opposed to “one unit per 30 seconds

How would that even be possible? Also what's are the start and end state here? Just pure assembly? Surely printing the PCBs can't possibly take a fraction of 30s. Neither can placing and SMD soldering the components.

I assume it’s final assembly

For that single factory line. Consumer electronics factories often have a lot of lines in parallel.

Yep, also minimum 2 lines to address SPOF (single point of failure).

Just because one little thing went wrong, you don’t stop the entire production line.

My guess is that they have 12+ parallel lines.