CLL Data Analysis & Reporting 2

Question 1

Which statistical measure is most useful for identifying the spread of process data around its mean?

Accepted Answer

Standard deviation

Answer

Standard deviation quantifies how much individual data points deviate from the mean, making it the primary measure of process spread.

Question 2

A Lean team notices their defect rate data forms a J-shaped distribution. What does this most likely indicate?

Accepted Answer

Rare events dominate the data

Answer

A J-shaped distribution typically indicates rare-event data where most values cluster near zero with a long tail, common in defect counts.

Question 3

What is the primary purpose of a control chart's upper and lower control limits (UCL/LCL)?

Accepted Answer

Indicate when a process has shifted to special cause variation

Answer

UCL and LCL are statistically derived at ±3 sigma to signal when special cause variation has entered the process.

Question 4

In a Lean data reporting cadence, what is the recommended frequency for reviewing operational KPIs on a visual management board?

Accepted Answer

Daily at shift start or standup

Answer

Daily review of KPIs on visual management boards enables rapid detection and response to problems before they escalate.

Question 5

A process capability index of Cpk = 0.85 tells a Lean analyst that:

Accepted Answer

The process does not meet the minimum capability threshold of 1.0

Answer

A Cpk below 1.0 indicates the process is not capable of consistently producing output within specification limits.

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