What is Six Sigma concept?

Six Sigma (6σ) is a systematic and data based approach to solve problem. The objective of Six Sigma  is to remove variation and reduce defect from process. Six Sigma is a process improvement tool.

Bill Smith American engineer introduced 6 sigma in 1986 while working in Motorola.

Six sigma (6σ) process is one in which 99.99966% of process is defect free. i.e. there is very less chance to have a defect in the process. Six sigma is profit making tool for business, i.e. 6σ tool is used to increase quality in process or increase production of process or make delivery of product faster or remove any non value added process, etc. Six Sigma is data based approach and root cause is analysed after statical analysis.

Philosophy of 6 sigma is based on DMAIC theroy. Where D is stand for Define, M is stand for Measure, A is stand for Analysis, I is stand for Improvement, C is stand for Control. Any 6 sigma project is solved in Five different phase.

Five different phases of 6 Sigma project:

1. Define phase:

In define phase problem is identified and brief description about problem is noted in term of monetary. Main problem is break into number of small problems. In define phase project charter is prepared, team is identified and champion and mentor is also defined in the same phase. 

The project is identify on the basis of the data collection of last couple of months or  year. Targets are identify on the basis of data and no abstract targets is defined. When selecting the problem or target one more thing is important to keep in mind is the voice of customer (VoC). It is important to know what exactly customer wants from the supplier.

Define phase is very important because it give brief description about the problem and if problem is well understood by team then team can work in the right direction and may solve problem easily.

2. Measure Phase:

Major phase is based on define phase, i.e data collection done in define phase is used in measure phase to identify the current value of the process, which is used to identify the baseline from where project will start. It is called measure phase as, we can compare the improvement done after project complete with this base line set in the measure phase.

3. Analysis Phase:

By this phase we reached to the middle of the six sigma theory, it is the third phase of Six Sigma methodology. The data collected by the team in the major phase used to identify problems for the deviation in the process or quality. Root cause (RCA: root cause analysis) is identified and work on the vital few. 

To identify potential cause t should sit together with expertise of different figures and do brainstorming for variation in process or quality. Once brain storming is done cause and cause and effect diagram of fish bone diagram should be prepared. After this all possible or potential causes are identified weather potential cause is deviated from the process or not, the deviated process is the main cause of variation in process or quality.

There can be a multiple of reasons for potential causes due to which process is debited than we have to decide which is more critical to process or which cause is effect more. 

When there are number of reasons for variation in process then we follow 80-20 rule in which 80% of problem is due to 20% of causes of variation, so we have to focus more on these 20% of causes which affect 80% of our problem. In other words we can say the team work on the vital few.

4. Improvement Phase:

Till now we did only collection of data and understand about the problem and also identify potential causes for variation in process or quality. Now the 4th phase of 6 sigma mythology is improvement phase, It is time to implement all  learning we did in previous phases. 

Main improvement of the project starts in this phase. To implement improvement we should do brainstorming again with the team and identify alternate solutions, poka-yoka, whether there is any requirement of change in documentation or change in process, all this idea can be generated during brainstorming.

Once we found improvement point, it's time to implement them and watch the result of implemented solution i.e check the effectiveness of the process if required there can be some changes in implemented points and after some changes implement them again and check the effectiveness on the process, if target is achieved according to our requirements or baseline, then this phase is completed.

One important point is to we know that if we not able to achieve the target as you decided define phase then we have to go back and start project from measure phase, till target is not achieved.

5. Control Phase:

Last phase of Six Sigma mythology is control phase in this phase we find improvement done during improvement phase. This phase is to ensure improvement remain sustain. 

The main activity in the Control phase is to control the improved process that decide in previous phases. The control phase is about ensuring the new process is implementing and Six sigma team handover improved process and changes done in documents like, FMEA, Setting approval check sheet, Control documents, etc to the process owner. The activities in Control phase are to create and update standard works or work instructions.

All the benefits, finding and changes done in the process due to project must be submitted to high management. Few managements also decide new six sigma project.

In the end of project, it is important to congratulate all the team members for their support by whom it is not possible to complete the project on time.

Certification of Six Sigma:

There are usually Five certificate or mostly saids belts, they are as follows:

1. White Belt: This is entry level where individual are guided about Six Sigma, and give overview about six sigma and about DMAIC Methodology. This is completely theoretical.

2. Yellow Belt:  This belt is award when a project is completed with use of DMAIC Methodology, It is can understand as Practical exam after theoretical exam.

3. Green Belt: In this level individual are learn about principles of six sigma and do a project under guidance of Black belt certified person. To get Green belts he/she must clear exam and complete project within the deadline.

4. Black Belt: Person is able to get Black belt when he/she is able to take six sigma project and execute with his team. To get six sigma Black belt certificate he must able to two to three sigma project.

5. Master Black Belt: Last but not the least Master Black belt certificate is owned by the person who is able to implement six sigma in different functions and guide different teams to complete their projects.