## Monday, 7 October 2013

### The Six Sigma Methodology

Inspection / QC of goods are often the last step at the conventional approaches to quality management in many operations.  Normally, only sample of the output are tested and corrective measure are taken if non-standard outputs were detected; however, this type of conventional approach is often unsatisfactory when it involves huge quantity of outputs and non-standard goods could easily slip through the net, leading to a bad name to the brand.

Over the years, the approach to quality control had changed.  The “six sigma” methodology introduced by Motorola in 1980’s helps to achieve consistent quality by identifying the variation in output. The “six sigma” refers to the culture for continuous quality improvement and to the six sigma statistical goal. The six sigma methodology is quantitative approach which avoids the variability in manufacturing processes and increases the reliability of products. The methodology follows the DMAIC cycle:

• Define – What needs to be improved?
• Measure – What’s the capabilities of the process at the current time? Is there variability in the process output and what are the averages?
• Analyse – Maps the process and the cause and effects then prioritise for action
• Improve – Simplify and change the process
• Control – Make the process more visible and use statistic process to control and monitor the performance.
The higher the value of sigma implies the more capability of manufacture in the process of delivering outputs which meets customer specifications.