Replacement cost and insured value for fixed asset

hi expers,

how do replacement cost factor and insured value factor fields in fixed assets group form affect to fixed asset value?

i don't understand about how use to this functionality. 

i try to enter 10 for replacement cost factor field and 10 for insured cost factor of a fixed asset. then i run update replacement cost and insured value, i don't see the affect to fixed asset value.