Thanks for providing some background to your statement. I just got an Invicta quartz with the Ronda "Swiss Parts" and I wasn't quite sure what it meant. From what you're saying Ronda provides specs both for their Swiss made movement AND specs for the Swiss (Ronda) parts movements that are assembled in Asia. Does this mean that Ronda oversees/controls the Asian manufacturing/assembly of their movements? I'm assuming that must be the case or how otherwise would they have specs for those models to compare them with their Swiss sourced and assembled movements. I guess it does make sense that the Asian parts models could use non-Ronda parts that are made with looser tolerances.
For some reason I assumed that Swiss parts movement meant simply the movement was assembled in Asia.
Ronda doesn't (currently?) list the specs differently for each location of manufacture. They list only one set of performance specs, regardless.
I don't know if Ronda oversees Asian manufacturing. I'd assume they at least audit the process from time to time. They definitely have to QC batch samples, probably locally and in Switzerland.
From what I can currently find, the only differences I see listed are the number of jewels (higher jewel count on the Swiss) and plating (gold on the Swiss vs nickel on the Asian) used. For some movements, they are the same.
They certainly wouldn't disclose the quantity of Swiss vs Asian components in either. Where the jewel count differs for the same movement caliber, I wouldn't think that the parts breakdown between the Swiss vs Asian production could be identical. Not sure what difference that otherwise makes, except, perhaps, longevity.
I also checked a few movements for ISA and ETA, and didn't see differences listed. I wish I could recall where I read the differences. It's probably best to take it with a grain of salt.
Maybe one of our resident watchmakers will chime in.
I found an 2009 post by lysanderxiii, on tz-uk.com here: http://www.tz-uk.com/forum/viewtopic.php?f=1&t=68258&p=785204#p711369
Here's the relevant quote:
Also, all of ETA's quartz movements were available in Swiss made and non-Swiss made.
955.xx2 or .xx1 are the Swiss ones
955.xx4 are the non-Swiss ones, these have slightly looser accuracy requirements, the Swiss are -0.3 to +0.5 s/d; the non-Swiss are -0.4 to +0.6 s/d.
It looks like ETA uses/used different calibers to denote their Swiss vs. Asian manufactures.
Don't know if it's accurate, but at least I know I wasn't imagining it. ;-)