Mathematical Expresion For Process Portability
Process portability test is usually conducted between testet sets in order to quantify their repeatability characteristics. One way to calculate process stability as a function of its portability is to use an algorithm which puts one process response value in the center of the specified tolerance range, and than examine the amount of “damage” caused by the deviation of that process response caused by others. The entire tested sets are sorted according to their contribution to process stability characteristics. The obtained stability maps represents process/design stability characteristics.