First Pas Yield vs Rolled Throughput Yield
Quality is the heart and soul of any production unit. And production means both productivity and efficiency of use of the materials used.
Many companies aim, even through KPI (Key Process Indicators) at the company level, to reduce their costs in order to reduce prices or to be able to withstand competition in the market, but also to reduce their probability of delivering non-compliant products to customers.
The first-pass yield (FPY), also known as the transfer yield, is an indicator of the production and quality performance of a line.
FPY is calculated by dividing the number of "good" units without reprocessing that come out of a process divided by the number of units that enter that process in a specified period of time.
First Pass Yield is the traditional indicator for process efficiency.
Many companies aim, even through KPI (Key Process Indicators) at the company level, to reduce their costs in order to reduce prices or to be able to withstand competition in the market, but also to reduce their probability of delivering non-compliant products to customers.
The first-pass yield (FPY), also known as the transfer yield, is an indicator of the production and quality performance of a line.
FPY is calculated by dividing the number of "good" units without reprocessing that come out of a process divided by the number of units that enter that process in a specified period of time.
First Pass Yield is the traditional indicator for process efficiency.
Its calculation formula is:
For example, for a production process where the inputs are 50 pieces and the outputs are 48 pieces, FPY is 96%.
It often happens that repairs in production sub-processes are not quantified. These re-processes occupy production capacity, increase costs, consumption and are directly related to what in quality is called COPQ (Cost of Poor Quality).
Rolled Throughput Yield (RTY) is a more appropriate indicator and a measure of process efficiency that takes into account losses due to repairs and scrap for all process steps.
Its calculation formula is:
Where RTYA, B, C are the partial yields of sub-processes A, B and C respectively.
For example for the next production process where partial FPYs are as in the figure:
Even if FPY is 96%, RTY is 0.92 x 0.94 x 0.877 = 0.7584. So RTY = 75.84%
The identified losses can be both the nature of the product quality and the technological ones.
FPY and RTY are very good starting points for improvement projects, including Six Sigma.
All that remains is to successfully carry out these projects and become more competitive.
Good luck!
