Question

Problem 1.Historical data is collected from an assembly process that consists of 5 operations. Determine the Rolled-Throughput Yield, Normalized Yield, Normalized Defects per Unit, and Total Defects per Unit (TDPU), given the following historical production data:

Operation	Opportunities per Unit	Units Produced	Defects Recorded
Build Rotating Group and Inspect	10	851	75
Install Rotating Group in Housing and Install Fittings	7	1202	72
Perform Functional Test	5	943	82
Clean and Paint with Final Inspection	3	894	70
Install Pulley and Labels	4	1200	88

Answer 1

Solution:

Rolled Throughtput Yield the probability that a manufacturing service complete all the required steps without any failures.

RTY = (R₁)(R₂)....................(R_n)

DPU = Total no of defects found in sample/Sample size

(1) Calculation for RTY

R₁ =1- 75/850 = .91

R₂ = 1-72/1202 = .94

R₃ = 1-83/943 = .80

R₄ = 1-70/894 = .92

R₅ = 1-88/1200 =.926

RTY = (R₁)(R₂)......(R₅)

RTY = (.91)(.94)(.80)(.92)(.926)

RTY = .582

(2) DPU Calculation

DPU₁ = 75/850 = 0.088

DPU₂ = 72/1202 = 0.059

DPU₃ = 83/943 = 0.088

DPU₄ = 70/894 = 0.078

DPU₅ = 88/1200 = 0.073

TDPU = 0.088+0.059+0.088+0.078+0.073

TDPU = 0.386