how so i apply a fatigue scatter factor
 

how so i apply a fatigue scatter factor
i have a requirement document that states "no major fatigue damage thru a 25500 flight hour / 17000 flight cycles for economical life, minimum scatter factor of 4"
does this mean that i need to test to 4 times the life, ie 4*25500 hrs or 4*17000 cycles? and do i also need to factor my fatigue calculations to show a factor of 4 on hrs/cycles?
duplicate thread ... see "aircraft engineering" forum