Six Sigma is a quality management methodology focused on reducing defects, variability, and waste in industrial and organizational processes. Its goal is to achieve an extremely high level of performance, where processes generate a maximum of 3.4 defects per million opportunities (DPMO).
Origin and Fundamentals
Created at Motorola in the 1980s, Six Sigma combines applied statistics, process control, a culture of continuous improvement, and customer focus. The term “sigma” refers to the standard deviation, a statistical measure of variation.
The higher the number of sigmas, the lower the probability of failures in a process.
Objectives of Six Sigma
- Reduce process variability
- Eliminate defects and non-conformities
- Improve perceived quality by the customer
- Increase efficiency and reduce costs
- Make decisions based on real data
Six Sigma Maturity Levels
| Sigma Level | DPMO (defects per million) | Quality Level |
|---|---|---|
| 2 Sigma | ~308,537 | Very low |
| 3 Sigma | ~66,807 | Acceptable in simple processes |
| 4 Sigma | ~6,210 | Medium quality |
| 5 Sigma | ~233 | High quality |
| 6 Sigma | 3.4 | Operational excellence |
DMAIC Methodology
For existing processes:
- D – Define the problem, the customer, and the requirements
- M – Measure the current process data
- A – Analyze root causes of variation
- I – Improve the process with corrective actions
- C – Control to maintain long-term gains
For new processes, DFSS (Design for Six Sigma) is used with a focus on preventing failures from the development stage.
Practical Applications with AJOLLY Testing
AJOLLY Testing applies Six Sigma principles in the phases of testing, validation, and industrialization of products, focusing on:
- Test stability with statistical analysis (CPK, PpK, Pareto of failures)
- Identification of process failures through real data captured in production
- Automation of data collection and analysis with test software and technical dashboards
- Continuous improvement with traceability by batch, operator, station, and result
- Integrated testability in design (DFT) to facilitate quality control from the start of the project
Benefits of the Six Sigma Approach with AJOLLY Testing
- Reduction of rework and rejections on the line
- Increase in FPY (First Pass Yield)
- Data-driven decision making
- Statistical reliability of tests
- Full support for quality certifications and audits (ISO, IATF, FDA)