Lean Six Sigma Methodology

Lean Six Sigma is a process improvement methodology that relies on a collaborative team effort to improve performance by systematically removing waste, combining Lean and Six Sigma to eliminate the eight kinds of waste

Lean Six Sigma projects comprise aspects of Lean’s waste elimination and the Six Sigma focus on reducing defects.

Lean Six Sigma utilizes the DMAIC (Define, Measure, Analyze, Improve and Control) phases similar to that of Six Sigma. Lean Six Sigma projects comprise aspects of Lean’s waste elimination and the Six Sigma focus on reducing defects, based on critical to quality (CTQ) characteristics.

Six Sigma use statistics tools for characterization and study of the processes, this is the reason of the name, as sigma is the standard deviation which gives an idea of the variability in a process and the goal of Six Sigma is to reduce it so that the process is always within the limits set by customer requirements.

Note: DPMO means Defects per million opportunities

1 sigma = 690,000 DPMO = 32% efficiency
2 sigma = 308,538 DPMO = 69% efficiency
3 sigma = 66,807 DPMO = 93.3% efficiency
4 sigma = 6.210 DPMO = 99.38% efficiency
5 sigma = 233 DPMO = 99.977% efficiency
6 sigma = 3.4 DPMO = 99.99966% efficiency
7 sigma = 0.019 DPMO = 99.9999981% efficiency

Lean is a systematic method for the elimination of waste (“Muda”) within a manufacturing system. Lean also takes into account waste created through overburden (“Muri”) and waste created through unevenness in work loads (“Mura”).

The eight muda are:

1.Transport (moving products that are not actually required to perform the processing
2.Inventory (all components, work in process, and finished product not being processed
3.Motion (people or equipment moving or walking more than is required to perform the processing
4.Waiting (waiting for the next production step, interruptions of production during shift change
5.Overproduction (production ahead of demand
6.Over Processing (resulting from poor tool or product design creating activity
7.Defects (the effort involved in inspecting for and fixing defects
8.Skills (waste of Skills, referred to as “under-utilizing capabilities and delegating tasks with inadequate training)

I created a presentation where I explain in details this topic, you can see my presentation here:


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