Question 1

Why is RTY better than final yield for measuring quality?

Accepted Answer

Final yield only counts units that ultimately pass, regardless of how many were reworked. A process could show 98% final yield while RTY is only 75%, meaning 25% of units needed rework. RTY exposes the 'hidden factory' — the rework loops, retests, and repairs that consume time and money without adding customer value.

Question 2

How do I improve RTY?

Accepted Answer

Focus on the step with the lowest FPY first, as it has the greatest impact on RTY. Use root cause analysis (5 Why, fishbone diagram) to identify why defects occur at that step. Common improvements include mistake-proofing (poka-yoke), better incoming material control, operator training, and tighter process parameter control.