The probability that a unit will go through a process defect free.

RTY = SUM[ ((Units Produced – Units with Defects) / Units Produced)*100]

Example:

To create the XX, it goes through three processes.

Process A Process B Process C Final Product
Units Produced = 1000 Units with Defects = 100 RTY = 90% Units Produced = 1000 Units with Defects = 300 RTY = 70% Units Produced = 1000 Units with Defects = 250 RTY = 75% Units Produced = 1000 Units Passed QE= 473 RTY = 47%

Out of 1000 units produced only 473 passed without any defects.