Page 188 - Six Sigma Demystified

168 Six SigMa DemystifieD

Recommended Tools

The following tools (discussed in detail in Part 3) are applicable to the improve
stage of DMAIC:

Defining the New Process

• Gantt charts and program evaluation and review techniques (PERT) analysis
help to verify the reduction in process critical- path cycle time.
• Five S tools help to reduce non- value- added cycle times owing to move-
ment, search time, ineffective use of floor space; to improve inventory
management; or to reduce accidents and improve working conditions.
• Level loading helps to balance the flow of orders.
• Box-whisker charts help to graphically compare before and after states of
process improvement.
• Cause- and- effect diagram help to generate a list of potential failure modes
that should be addressed in the solution.
• Designed experiments, factorial designs, regression analysis, residuals analysis,
response surface analysis, evolutionary operations, interaction plots, and con-
tour plots help to determine where a maximum or minimum response is
expected within or close to the data range.

Assessing Benefits of the Proposed Solutions

• Matrix diagrams and prioritization matrices help to ensure that process
solutions are aligned with customer needs.

Evaluating Process Failure Modes
• Procession decision program charts and failure modes and effects analysis
(FMEA) help to determine high- risk process activities or product features
in the proposed improvement.

Implementation Verification

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• Flowcharts and process maps help to define the process- evel activities nec-
essary.
• Hypothesis testing of two samples and nonparametric test on the equality of
means help to compare process averages after improvements versus base-
line estimates.