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Chapter 5: Basic Six Sigma Concepts - Coggle Diagram
Chapter 5: Basic Six Sigma Concepts
Six Sigma & Variation
Goal: Cut down on flaws to boost output, cut expenses, and increase revenue.
Key Takeaway: Correcting the process is necessary before eliminating differences to guarantee quality.
Overview of Standard Deviation (σ)
Evaluates a data set's variability in relation to the mean.
Small σ: Data points have little change and are near the mean.
Large σ: There is a lot of variety in the data points.
Symbolized by the Greek letter σ, which stands for "sigma."
How to Determine Standard Deviation (For Test Results, for Example)
Determine the Mean (μ)
Divide the total number of data points (N) by their sum.
Square the Differences and Subtract the Mean
Determine (xᵢ - μ)² for every data point.
Calculate the Variance (σ²).
Divide by N after adding up all of the squared differences.
Determine the Variance's Square Root.
9.987 is the standard deviation, σ = -99.76.
Six Sigma application
Defect reduction can be assisted by teams' knowledge of variety.
In practice, standard deviation is usually computed using statistical software.
Why Use Sample Information?
For operational or financial reasons, complete demographic data is frequently unavailable.
Population characteristics are estimated using sample data.
Process for Computing the Sample Standard Deviation
Determine the Mean (x̄).
Divide the total number of values by N, or the number of data points.
Square the Differences and Subtract the Mean
Determine (xᵢ - x̄)² for every data point.
Calculate the Variance (s2)
Divide the total squared differences by N-1 (8).
Determine the Variance's Square Root.
√Variance = standard deviation s
Why Do Standard Deviation Calculations?
Explains process variance while taking outliers into consideration.
Directs more statistical analysis and Six Sigma process enhancements.
Important to Six Sigma's Statistical Process Control (SPC).
Pareto Principle (rule of 80/20):
80% of impacts result from 20% of causes.
Assists in identifying the most important reasons for process improvement.
The Pareto chart
Graphical tool for ranking causes according to their effect or frequency.
Helpful in determining the main factors causing an issue.
VOC (voice of the customer):
Proactive feedback method to better goods and services.
VOC makes requirements and problems more clear and guarantees client happiness.