Rolled Throughput Yield (RTY)

Rolled Throughput Yield is the probability of the entire process producing zero defects. RTY is more important as a metric to use where the process has excessive rework.

Since this rework involves many of the 7-wastes and contains the hidden factory opportunity, it is relevant to guide the team in the right direction.

RTY is the product of each process’s throughput yield, TPY.

Using the same process as shown in the TPY example:

RTY = Process 1 TPY * Process 2 TPY * Process 3 TPY

RTY = 0.800 * 0.739 * 0.804

RTY = 0.475 = 47.5%

There is a 47.5% of the entire process producing zero defects.

RTY and other yield metrics can serve as baseline scores (Measure Phase) and final scores for Six Sigma projects (Control Phase).

The baseline score provided in the MEASURE phase does not have to be a z-score and often the yield metrics are easier for team and other company employees to relate with and understand.

Another formula is shown below to estimate RTY if the defects per unit or defects and units are known:

More YIELD calculations

Throughput Yield, TPY.

Normalized Yield, NY.