Throughput Yield is a metric that gives the probability that a unit will pass through a single step in the process completely defect free. It is used in the calculation of Rolled Throughput Yield, which gives the probability of a unit passing through all the steps in the process without Defects.
Consider a three step process to manufacture a product:
the number of opportunities for a defect in each of the steps is 10, 10 and 20 respectively.
100 units of product are manufactured using this process.
The number of defects at each step is found to be 13, 7 and 5 respectively.
To calculate the throughput yield for step one, the number of defects in step 1 (13) is subtracted from the total number of units processed (100) and the result (87) is divided by the total units processed (100) to yield 0.87 or 87%. The throughput yields for the remaining steps is calculated similarly, giving 93% and 95% respectively.
The Rolled throughput yield is then calculated by multiplying the throughput yields of the individual process steps together. In this case, rolled throughput yield = 0.87*0.93*0.95 = 0.77 or 77%.