FREE Lean Six Sigma Green Belt DMAIC: Analyze Phase Techniques Questions and Answers

Question 1

A project team in a manufacturing plant is analyzing data to understand the relationship between oven temperature (an input variable, or 'x') and the resulting product hardness (an output variable, or 'y'). Both variables are continuous. Which statistical tool is MOST appropriate for quantifying the strength and nature of this relationship?

Accepted Answer

Regression Analysis

Answer

Regression Analysis is used to model the relationship between a dependent (output) variable and one or more independent (input) variables. Since the team wants to understand how temperature ('x') affects hardness ('y'), regression is the ideal tool to create a predictive equation and quantify the relationship.

Question 2

What is the primary purpose of conducting a hypothesis test during the Analyze phase of a DMAIC project?

Accepted Answer

To statistically validate whether a suspected root cause has a significant effect on the process output.

Answer

Hypothesis testing is a statistical method used to make decisions based on data. In the Analyze phase, it is used to test theories about root causes. For example, a team might hypothesize that 'Shift A' has a different average cycle time than 'Shift B'. A hypothesis test (like a t-test) would determine if the observed difference is statistically significant or just due to random chance.

Question 3

A team is struggling with a high rate of shipping errors. They have gathered experts from the warehouse, sales, and data entry departments for a brainstorming session to identify all potential causes for the errors. Which of the following tools would be most effective for structuring this brainstorming session and categorizing the potential causes?

Accepted Answer

Fishbone (Ishikawa) Diagram

Answer

A Fishbone (or Ishikawa) Diagram is a visual tool used to categorize and display the potential causes of a specific effect or problem. It is ideal for brainstorming sessions as it helps organize thoughts into logical categories (like Manpower, Method, Machine, Material, etc.), ensuring a comprehensive exploration of potential root causes.

Question 4

After brainstorming numerous potential causes for late deliveries, a project team has collected data on the frequency of each cause. They now need to prioritize their efforts by focusing on the causes that contribute most to the problem. Which tool should they use?

Accepted Answer

Pareto Chart

Answer

A Pareto Chart is a bar chart that displays the frequency or impact of causes in descending order, combined with a line graph showing the cumulative percentage. It is based on the Pareto Principle (80/20 rule) and is specifically designed to help teams identify and prioritize the 'vital few' causes that are responsible for the majority of the problems.

Question 5

Which of the following BEST describes the primary function of the 5 Whys technique in the Analyze phase?

Accepted Answer

To systematically drill down past symptoms to identify the fundamental root cause of a problem.

Answer

The 5 Whys is an iterative interrogative technique used to explore the cause-and-effect relationships underlying a particular problem. By repeatedly asking 'Why?', the team can move beyond the immediate symptoms and uncover a deeper, more fundamental root cause that, when addressed, can prevent the problem from recurring.

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification Practice Test

FREE Lean Six Sigma Green Belt DMAIC: Analyze Phase Techniques Questions and Answers