CRE CRE Corrective Action and Continuous Improvement 2

Question 1

The primary Six Sigma metric for measuring process capability is expressed as:

Accepted Answer

Process sigma level, where 6σ corresponds to 3.4 defects per million opportunities

Answer

Six Sigma defines process quality in terms of sigma level; a 6σ process produces only 3.4 DPMO.

Question 2

On a standard control chart, the Upper Control Limit (UCL) is typically set at:

Accepted Answer

3 standard deviations above the process mean

Answer

Control limits at ±3σ from the mean represent the bounds of natural process variation with approximately 99.73% of data within limits.

Question 3

Which type of control chart is used to monitor the fraction (proportion) of defective items in a process?

Accepted Answer

p-chart

Answer

The p-chart monitors the proportion of nonconforming items in each sample and is used for attribute data.

Question 4

Design of Experiments (DOE) in reliability improvement is used to:

Accepted Answer

Systematically study the effect of multiple factors on a reliability response

Answer

DOE allows engineers to efficiently evaluate main effects and interactions of multiple variables on reliability simultaneously.

Question 5

Reliability Growth testing using the Duane postulate tracks improvement by monitoring:

Accepted Answer

Increasing cumulative MTBF as failures are discovered and corrected during development

Answer

The Duane model plots cumulative failures versus cumulative test time on log-log paper to demonstrate reliability improvement.

(CRE) Certified Reliability Engineer Practice Test