Is throughput yield the same as FPY or FTY? Rolled Throughput Yield

[ProblemChild]

I understand that First Pass Yield (FPY) does not include reworked units in the calculation, but First time Yield (FTY) does.

What I am confused from the internet is that some people are saying Throughput yield is the same as FPY, while others are linking throughput yield to FTY instead.

Who is right?


I am trying to explain how to calculate rolled throughput yield ….

Do we multiply FPYs from different processes, or use the FTYs instead??

Thanks

 

[japayson]

It seems to me that Rolled Throughput Yield should not include reworked units.

 

[AndyN]

I understand that First Pass Yield (FPY) does not include reworked units in the calculation, but First time Yield (FTY) does.

What I am confused from the internet is that some people are saying Throughput yield is the same as FPY, while others are linking throughput yield to FTY instead.

Who is right?


I am trying to explain how to calculate rolled throughput yield ….

Do we multiply FPYs from different processes, or use the FTYs instead??

Thanks

First pass means just that. Any rework or situation where you don't make 100%, shouldn't be included.

 

[Bev D]

the root of your confusion lies in AndyN's tag line. words have multiple meanings that are often arbitrarily used and heard. the truth lies in the formulas.

I have heard FPY and FTY used interchangeably. so let me take the semantics out of it and use A type yield and B type yield.

A) Some people consider yield to be an absolute: I put 100 units and I scrapped 2 so my yield is 98%. Rework doesn't count in this case as it will eventually yield as an acceptable, shippable unit.

B) Six Sigma and 'lean' thinking add rework as yield loss because the reworked units had a defect and to the 'new' way of quality thinking all defects should be eliminated as they are waste.

"Rolled" throughput yield is the multiplication of the (B) yield at each station or operation.