▁and ▁the ▁window ▁limits . ▁The ▁center ▁of ▁the ▁process ▁window ▁is ▁defined ▁as ▁zero , ▁and ▁the ▁extreme ▁edges ▁of ▁the ▁process ▁window ▁are ▁ ± 9 9 %. ▁A ▁P WI ▁greater ▁than ▁or ▁equal ▁to ▁ 1 0 0 % ▁indicates ▁that ▁the ▁profile ▁does ▁not ▁process ▁the ▁product ▁within ▁specification . ▁A ▁P WI ▁of ▁ 9 9 % ▁indicates ▁that ▁the ▁profile ▁ ▁runs ▁at ▁the ▁edge ▁of ▁the ▁process ▁window . ▁For ▁example , ▁if ▁the ▁process ▁mean ▁is ▁set ▁at ▁ 2 0 0   ° C , ▁with ▁the ▁process ▁window ▁cal ibr ated ▁at ▁ 1 8 0   ° C ▁and ▁ 2 2 0   ° C ▁respectively ; ▁then ▁a ▁measured ▁value ▁of ▁ 1 8 8   ° C ▁transl ates ▁to ▁a ▁process ▁window ▁index ▁of ▁− 6 0 %. ▁ ▁A ▁lower ▁P WI ▁value ▁indicates ▁a ▁more ▁robust ▁profile . ▁For ▁maximum ▁efficiency , ▁separate ▁P WI ▁values ▁are ▁computed ▁for ▁peak , ▁slope , ▁re flow , ▁and ▁so ak ▁processes ▁of ▁a ▁thermal ▁profile . ▁▁ ▁To ▁avoid ▁▁ ▁thermal ▁shock ▁affect ing ▁production , ▁the ▁ste ep est ▁slope ▁in ▁the ▁thermal ▁profile ▁is ▁determined ▁and ▁le ve led . ▁Man ufact ur ers ▁use ▁custom - built ▁software ▁to ▁accur ately ▁determine ▁and ▁decrease ▁the ▁ste ep ness ▁of ▁the ▁slope . ▁In ▁addition , ▁the ▁software ▁also ▁automatically ▁re cal ibr ates ▁the ▁P WI ▁values ▁for ▁the ▁peak , ▁slope ,