The Six Sigma Process - What is it?

by Peter Peterka1 Sigma, the word which forms the core of this process is derived from the Greek alphabet and is used to represent the standard deviation of a statistical population. The term Six Sigma process arrives from the belief that if one has six standard deviations between the standard specification limit and the mean, there will be a few or no item that fails to meet the specifications. This study is based on the calculation model which is used in a process capability study where the number of standard deviations that occur between the mean and the nearest specification is in sigma units. What happens here is that once the process standard deviation rises, fewer standard deviations will find its place between the nearest specification limit and the mean, which in turn will decrease the sigma number. It has been studied that processes do not perform in the long run, thus, the number of sigmas that fit between the processes mean and the nearest specification limit might drop over time. It is to cater to this real-life increase in variation over time that an empirically based 1.5 sigma shift was introduced in the six sigma calculation. It is from this idea that the process that fits the process mean and the nearest specification limit in a short-term study will in the long run fit 4.5 sigmas. This study finally gives rise to the widely accepted definition of the Six Sigma process, which produces 3.4 defective parts out of per million opportunities. To sum up, we can say that the Six Sigma process corresponds to 4.5 sigmas, which is namely 6 sigmas minus the 1.5 sigma shift which is introduced in order to account for the long-term variation. Basically the Six Sigma process is very specific as it uses clearly defined steps and methodologies. In this process, a problem is defined and then the Six Sigma team takes steps to find a solution that will result in monetary gain. Projects that form the core of the Six Sigma process involves data, measurements and decisions based on fact. The Six Sigma process involves five steps that are enumerated below. - Define: In this stage, the problem is specified in very clear terms. It is very important to find the root cause at this stage so that steps can be taken to measure that it has improved. - Measure: Data that covers a wide of issues is collected at this stage. For e.g., in the case of manufacturing, this data could cover the measurements of a specific product, such as its height, weight, diameter or other attributes. To ensure that there is enough information for statistical validity it is important to collect data from multiple samples. - Analyze: This stage is used for the statistical and scientific analysis of data, which is then presented in the form of graphs and charts. In most organizations, software is used to create these graphs. - Improvement: In this stage it is time to make improvements based on the information that has been gathered. This improvement could range from something really small to something more complex. - Control: This is the stage when new improvements are included into the methods a business uses to ensure that it is meeting certain requirements. Peter Peterka is the President of SixSigma.us. For information on Six Sigma, Six Sigma Yellow Belt or Six Sigma White Belt programs contact Peter Peterka. Article Source: http://www.articlerich.com