An Overview of Six Sigma
This article was originally published at www.idatix.com
In this post I look at the oft criticised but much used, Six Sigma...
Origins & Popularity
Although invented by Motorola in the nineteen eighties, Six Sigma’s rise to global popularity was not just as a result of Motorola’s success with the method. GE boss Jack Welch became the poster boy of Six Sigma as GE hurtled toward a committed path of making Six Sigma part of their organisation’s “DNA”.
The wave of enthusiasm that resulted from the cost cutting success of Motorola and GE spawned a whole generation of Six Sigma consultants and an entire industry in Six Sigma training. The frenzy of process improvement opportunity within manufacturing quickly transferred to services businesses who expanded the method across their international boundaries.
How it works
Six Sigma has a defined structure by which projects are undertaken. The DMAIC approach focusses on improving existing processes whilst the DMADV approach focusses on the design of new processes:
- Define what is required to be improved
- Measure the process
- Analyze the data
- Improve the current process
- Control the improved process
- Define the design of the new process
- Measure required capabilities
- Analyze options
- Design the process
- Verify the selected process design
Each of these approaches require significant measurement and data analysis, commonly using a range of statistical techniques ranging from the simple Pareto Chart to more complex tools such as Control Charts and even data analysis software such as Minitab.
Six Sigma has been heavily criticized for a number of reasons. Those businesses operating in service environments have been reluctant to indulge in heavy statistical analysis which is seen to be inappropriate in non-manufacturing environments where the focus is on knowledge work rather than measuring “widgets”. Furthermore Six Sigma has been criticised for being too time consuming to implement projects and for the fact that its focus is on improving existing processes blindly rather than questioning whether the process should actually exist at all.
When used in a practical manner, Six Sigma can be an excellent means of identifying where key process problems occur. Whilst not all of the statistical methods are required for every situation there are several excellent tools which can help to improve processes. Some of the most useful of these tools are the most simple, such as The Five Whys and SIPOC Analysis.