Basic scale definition:
1/144 means one length unit on the model represents 144 length units on the real object. The length units can be any unit you desire - inches, feet, meters, millimeters, furlongs, light years, etc.. Notice that the length units are the same. Typically when you see a fraction with a denominator to a power of two it is typically in English units. In this case, one inch represents 144 inches (12 feet).
I don't know the exact width of a CVE's flight deck planking, but I suspect it's about three inches. At 1/144 scale this is 3/144 inches = 1/48 inches ~ 0.02 inches ~ 0.5 mm.
Hope this helps and happy modeling!