Six Sigma Calculator

Six Sigma is a very useful methodology for process improvement and quality management. It focuses on identifying and eliminating defects in any process, aiming for near perfection.

But it requires a structured approach and the right tools to be effective. That's where my Six Sigma Calculator comes in. Instead of using an Excel spreadsheet, I developed a dedicated Python-based desktop application.

The goal was to ease the process of applying Six Sigma methodologies by providing a user-friendly interface for data input, analysis, and visualization.

Not gonna lie, Claude 4 helped me a lot during the development process.

Python libraries

Built with Python and Tkinter for GUI, NumPy, Pandas, Matplotlib, and SciPy for robust data handling and visualization.

How does it work?

Users import measurement data via CSV, set specification limits, and calculate metrics with a single click. The tool generates histograms and detailed reports.

Source code available on GitHub.

Reporting

The calculator generates comprehensive reports with process capability indices and statistical analysis. Here's an example output from a sample dataset:

SIX SIGMA PROCESS CAPABILITY ANALYSIS
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📊 BASIC STATISTICS:
Sample Size (n): 601
Mean (μ): 500.0841
Standard Deviation (σ): 0.3398
Range: 4.7000

⚙️ SPECIFICATION LIMITS:
Upper Spec Limit (USL): 502.0000
Lower Spec Limit (LSL): 498.0000
Target Value: 500.0000
Spec Width: 4.0000

🎯 PROCESS CAPABILITY INDICES:
Cp (Potential Capability): 1.9622
Cpk (Actual Capability): 1.8797
Cpu (Upper Capability): 1.8797
Cpl (Lower Capability): 2.0447
Cpm (Taguchi Index): 1.9047

📋 PROCESS METRICS:
Yield within Spec: 99.50%
Sigma Level: 7.14σ
Process Centering: 0.0841

🔍 INTERPRETATION:
Cp/Cpk ≥ 1.33: Capable process
Cp/Cpk ≥ 1.00: Marginally capable
Cp/Cpk < 1.00: Incapable process

🎯 CURRENT STATUS: ✅ CAPABLE PROCESS

/* This analysis demonstrates a highly capable process with excellent control and minimal variation. The process consistently meets specification requirements with a 99.50% yield rate and operates at a 7.14 sigma level. */