Creating a SIPOC Chart
February 12, 2025
Recently the Dow Jones index faced a drastic fall. This fall was partly because of the fears of inflation that were sparked by increasing employee wages. This is because employee wages have been stagnant in America for close to a decade now. The drastic short-term rise was attributed by many to be the result of […]
The relations between India and Pakistan have never really been cordial. Ever, since the Islamic Republic of Pakistan was carved out of British India, the two countries have been at loggerheads. The countries have fought four wars until now, and the disputed territory of Kashmir has been at the centre of three of those wars. […]
Enterprise Resource Planning (ERP) and Business Process Re-engineering (BPR) evolved almost at the same time i.e. 1st half of 1990. Both relates to radical redesign of an organization at a relatively short period. Both are having the primary intend to optimize workflow and improve productivity. But, the chicken and egg question remained, whether an organization […]
The Voice of Customer may sound like a simple exercise. However it would be safe to say that reading at the literature makes it look deceptively simple. Anyone who has an experience with market research will understand the issues involved. For a Six Sigma project to be successful, the Voice Of Customer must be accurate. […]
Project integration management refers to the process of tying everything in place. Integration management deals with: Developing the Project Charter and Project Scope statement (Initiating Process Group), Develop Project Management Plan (Planning process group), Direct and Manage project execution (Executing Process group). Hence this is process that integrates all the disparate processes and provides a […]
One of the greatest criticisms that have been mounted against the six sigma methodology is the fact that there is a possibility that the entire system is built on fudged numbers. Statisticians have claimed that the name six sigma is misleading. Here are the reasons why:
The statistical term Six Sigma actually refers to a process in which there will be 2 defects per billion times the process is run. However, the definition of Six Sigma accepted by modern day practitioners is a much easier to follow, 3.4 defects per million. Although even achieving efficiency of 3.4 defects per million, makes the process achieve near zero and therefore negligible defects, the statistical name 6 sigma is misleading. The values 3.4 defects per million, in reality, correspond to 4.5 sigma levels. The balance is accounted for by the 1.5 sigma shift.
The logic behind the 1.5 sigma shift is rooted in empirical studies. Empirical studies have shown that processes tend to fare better in the short term than they actually do in the long term. This is because in the short term, there is only normal process variation that needs to be dealt with. However in the long term cases of special process variation also occur. This results in the process performing at 6 sigma levels in the short run but at 4.5 sigma levels in the long run.
The long term variation in the process variation is accounted for by one of the two reasons:
As a result of either of the above reasons, or a combination of both, the process fails to meet its Six Sigma objectives. This phenomenon is called long term dynamic mean variation.
Now, we know that the Six Sigma criteria are not met because of long term dynamic mean variation. But how do we know that we need to remove 1.5 sigma from both sides of the normal curve. Well, it isn’t a statistical reality but just an industry convention.
Motorola was the pioneer of Six Sigma methodology worldwide. They have made empirical studies about the processes that they have improved and concluded that a 1.5 sigma shift occurs. While many statisticians have called this 1.5 sigma shift arbitrary, the industry wants to go the Motorola Way and 3.4 defects per million which define 4.5 Sigma have become an industry wide accepted definition of a Six Sigma process.
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