# Rolled Throughput Yield

Discussion in 'Lean, Six Sigma and DFSS' started by mk241, Sep 9, 2020.

1. ### mk241Member

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Hi,

I am trying to understand RTY and implement into our system.

We are making lights built with PCA's with LED mounted, 2 driver boards and cover etc; after assembling them all, we put them in a series of tests (say testing 1 to 3).

Now I am trying to capture in the following sequential order for making 25 lights.

Step 1. Assemble 12 x LED boards and 1 x driver A board and 1 x driver B board to main base for 1 light, meaning I need 300 x LED board and 15 x driver A boards and 15 x driver B boards for 25 lights

Step 2. Function Testing

Step 3. Burn In testing

Step 4. Pressure testing

Here my question is that if we have scrap or rework from LED boards or driver boards in step 1, how do I have to calculate FTY in step 1? From Step 2 to 4, the maximum good units will be only 25 as we are building for 25 lights only. How can I roll over from step 1 with following failures to step 2 to 4?

Scrap - 4 LED boards
Rework - 4 LED boards
Scrap - 1 Driver A board
Rework - 1 Driver B board

Hope my question is clear.

Regards,
Minki

2. ### Bev DModeratorStaff Member

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You treat each step independently for FTY. The denominator is always 25 if you always submit 25 assemblies to each step.

Rolled throughput yield is the product of the FTY at each step...

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3. ### Andy NicholsModeratorStaff Member

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FTY = ?

4. ### MinerModeratorStaff Member

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Probably First Time Yield, though First Pass Yield is the more common term.

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5. ### Andy NicholsModeratorStaff Member

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Agreed! Thanks.

6. ### nibin k kNew Member

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Yes
I remember we introduced RTY part of ACE certification in United technologies

7. ### MinerModeratorStaff Member

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