Study of the relation between Loading ratio and X-Factor

In the semiconductor FAB, Lead-Time of a product is required to be decrease as much as possible for customer demands. Investigation of an influence parameter about X- Factor of a product is needed to discuss how Lead-Time shortens. The own simulation calculated X-Factor when a type and a parameter of equipment is changed. By this simulation, X- Factor by each process depended on loading ratio of equipment, and it became clear that it in particular was affected by a fluctuation of Down-time greatly. On the other hand as for X-Factor is not almost influenced the fluctuation of Up-time and length of processing time.