Statistical Quality Control. Bhisham C. Gupta

many business initiatives, Six Sigma implementation can fail because of poor management execution and lack of support. Organizations new to Six Sigma should be aware of the dangers that poor leadership, cultural integration, and project selection can have on a Six Sigma implementation [5]:

       Lack of leadership strategy and commitment:Following the “more is more” approach, companies implement so many projects that too many resources are pulled away from everyday operations and new product development. Customer satisfaction and the R&D pipeline both suffer.Leaders expect superior results too quickly.After initial success, management decides to move on to the next “new thing.”

       Poor cultural integration:Leaders fail to communicate progress throughout the training period.The Black Belt role is not fully supported by management.Six Sigma is treated as an “extra assignment” and perceived as a burden.

       Poor project selection and assignment:Projects are not tied to customer requirements or the business strategy.Projects concentrate on improving local processes and ignore the big picture.Projects are assigned with leadership’s suggestions on fixes and root causes.For references [2], [3], [4] and [5] see the End Notes given on the last page of the Bibliography Section.

Review Practice Problems

      1 In which phase of the Six Sigma project does the team identify root causes of the problem?

      2 A well‐behaved process is currently running at a 5σ level. What is the expected number of defects per million opportunities (DPMO) if the mean of the process shifts by 1.5 standard deviations?

      3 Using the Six Sigma methodology, a team improves a process, bringing the sigma level from up 1σ to 3σ. What is the resulting change in the long‐term defect rate?

      4 In what ways is Six Sigma similar to other quality initiatives?

      5 In what ways is Six Sigma different from other quality initiatives?

      6 List and explain the differences between the goals of Six Sigma and the goals of Lean.

      7 What is the main difference between the Basic 7 tools and the New 7 Tools?

      8 Think of the last time you bought lunch at a fast‐food restaurant. Use the Eight Wastes as a guide to identify wastes that you observed.

      9 In what way is the Control phase of the DMAIC cycle similar to the last stage of the 5S method?

      10 Give three examples of mistake‐proofing devices that can be found in everyday life. For each, indicate whether the mistake‐proofing feature is a control or warning, or if it completely eliminates the mistake.