Definition
The share of good units in the output of one operation or one process; the denominator can be either the input quantity or the total output quantity, depending on how it is tallied. It is counted per operation, while the multiplied result across a whole process is called first pass yield (FPY), also known as rolled throughput yield (RTY).
In detail
Yield is one of the easiest measures to fudge through its basis: whether rework counts as good, whether scrap is included, whether the denominator is input or output — four combinations give four different numbers. The quality rate inside OEE is a yield, with the output of that operation as the denominator. The yield of a whole process is not the average of the operations but their product, so five operations at 95 percentage points each leave only about 77 — which is exactly why first pass yield (also called rolled throughput yield, RTY) is a separate measure.
Example in practice
On a five-operation line every operation shows a yield above 95 percentage points and the board is all green. Multiplying the five gives a first pass yield of only 77, and once rework hours are counted the team finds rework consuming three tenths of capacity.