Six Sigma is fundamentally a type of business management strategy that dates back to the 1980’s. It was first devised in the USA and was implemented within the Motorola company and it is still widely used today and shows no sign of losing its popularity.
Six Sigma, as a strategy looks at ways in which outputs can be improved by removing errors and ensuring that all the processes and manufacturing techniques used within the business are not variable.
The process is highly reliant on using quality management techniques and is also linked intrinsically to the use of statistics to help shape the business. But in addition, it creates experts within the company who can take responsibility for quality. These are divided into various groups. Starting off with senior management who are the Executive Leaders, then there are Champions, Master Black Belts, Black Belts, Green Belts and Yellow Belts. Yellow Belts are usually those who are closest to the production line.
Every time a Six Sigma process is carried out, it will follow a very rigid sequence of procedures and has defined targets. There are however, 2 methodologies which are namely DMADV and DMAIC.
DMAIC is an acronym that has 5 very distinct phases, but each has to be gone through.
1. Define. Define refers to defining the problem and the project goals. What is to be achieved from carrying out this exercise?
2. Measure. This relates to collecting all the data required to carrying out the exercise and making sure that the current processes and procedures are also measured.
3. Analyse. All the data that has been gathered needs to be analysed so that all cause and effect dynamics can be understood. The dynamic also have to be analysed so that a full picture of the key cause and effect relationships can be secured. The root cause or bottom line of any aspect of the cause and effect relationship, which is causing a defect, also has to be hunted down.
4. Improve. The current process which has resulted in a defect being caused needs to be improved, to reduce the occurrence of the defect. These improvements will be carried out using mistake proofing or poka yoke techniques to ensure that the new process will eliminate errors and no defects will result.
One interesting aspect of the improvement phase is that it also requires the new process that has been devised will be tested to ensure that it does indeed eliminate the defects. So the improvements are not just about getting rid of an old and inefficient way of doing something, but it is also about devising a better way of doing it and then testing the new process, rather than just assume that it will be better than the previous system.
5. Control. Control is about ensuing that the system or process that is going to be introduced will be capable of correcting anything that goes ‘off target’ before it results in a defect. However, there will not be simply one control system but several, including visual control by personnel, production boards or even the use of statistical processes.
The Six Sigma Process including the DMAIC method of achieving quality is not without its critics, however, many people feel that through involving workers at all different levels within the process, there is a greater feeling of ownership and involvement. Also if staff are involved in making changes to processes, then they are less likely to be resistant to the new processes coming in, because they have been involved and have a good understanding of why the changes have come about.