Create a service example to explain rolled throughput yield, DPO, DPMO, process sigma. Answer: A service has 4 steps and each step has only one opportunity for a defect. The yield of step 1 is 0.99…

Question

Options

• AA service has 4 steps and each step has only one opportunity for a defect. The yield of step 1 is 0.99, the yield of step 2 is 0.95, the yield of step 3 is 0.99, and the yield of step 4 is 0.97. The four steps are independent of each other. What is the rolled throughput yield (RTY), the DPO, the DPMO, and the process sigma? RTY=.99x.95x.99x.97=.903 DPO=1.0-RTY=.097 DPMO=97,000 Process Sigma=approx 2.8

• A
  100% (42)

Explanation

Option A is correct because it accurately applies all four Six Sigma metrics in sequence: RTY is the product of each step's individual yield (0.99 × 0.95 × 0.99 × 0.97 = 0.903), meaning roughly 90.3% of units complete all four steps defect-free. Since each step has only one opportunity for a defect, DPO equals the overall defect probability (1 − RTY = 0.097), and scaling to a million opportunities gives DPMO = 97,000. A DPMO of 97,000 corresponds to approximately 2.8 sigma on the standard conversion table. There are no distractors here - this is the model answer demonstrating the correct chain of calculations.

Memory tip: Think of the metrics as a cascade - RTY multiplies yields (the "chain of survival"), DPO flips RTY to get defect probability, DPMO just moves the decimal six places right, and Process Sigma is looked up from a standard table. The key insight is that with one opportunity per step, DPO = 1 − RTY directly; if there were multiple opportunities per step, you'd divide by total opportunities first.

No community discussion yet for this question.