![]() The Process capability measures indicates the following The process capability is calculated using the formula CP = USL-LSL/6 * Standard Deviation where CP = process capability index, USL = Upper Specification Limit and LSL = Lower Specification Limit. Capability analyses is done in measure phase. In the Measure phase we collect all the data as per the relationship to the voice ofcustomer and relevantly analyze using statistical formulas as given in the above table. For example headache is the effect and the causes are stress, eye strain, fever if you remove this causes automatically the headache is removed this is implemented in Six Sigma by using the Fishbone or Ishikawa diagram invented by Dr Kaoru Ishikawa. The most important equation of Six Sigma is Y = f(x) where Y is the effect and x are the causes so if you remove the causes you remove the effect of the defect. Mode is the most frequently observed measurement in the diameter of the piston that is if 2 pistons out 10 samples collected have the diameter as 6.3 & 6.3 then this is the mode of the sample and median is the midpoint of the observations of the diameter of the piston when arranged in sorted order.įrom the example of the piston we find that the formulas of mean, median, mode does not correctly depict variation in the diameter of the piston manufactured by the factory but standard deviation formula helps us toįind the variance in the diameter of the piston manufactured which is varying from the customer mentioned upper specification limit and lower specification limit. In the above table X, Xi are the measures of the diameter of the piston and µ, XBar is the average. Where mean is the average for example if you have taken 10 sample of pistons randomly from the factory and measured their diameter the average would be sum of the diameter of the 10 pistons divided by 10 where 10 the number of observations the sum in statistics is denoted by ∑. Now we will get into the formulas of Six Sigma which is shown in the table below.Ĭentral tendency is defined as the tendency for the values of a random variable to cluster round its mean, mode, or median. Defining Project task is typically complex and accomplished by a series of decomposition followed by a series of aggregations it is also called top down approach and can be used in the Define phase of Six Sigma framework. It is a process for defining the final and intermediate products of a project and their relationship. Project schedule (using GANTT or PERT as an attachment).Project objective or purpose, including the business need addressed.Project charters the charter documents the why, how, who and when of a project include the following elements Define the Process (top-level) and its stake holders.The objectives within the Define Phase which is first phase in DMAIC framework of Six Sigma are:. We will discuss each phase in brief and the various methods used in Six Sigma. . Six Sigma is implemented in five phases which are Define, Measure, Analyze, Improve, Control. The father of Six Sigma is Bill Smith who coined the term Six Sigma and implemented it in Motorola in the 1980’s. Six Sigma is Denoted by the Greek alphabet σ which is shown in the table above and is called as Standard deviation. ![]() ![]() One more example would say a company manufactures pistons used in motor cycles the customer demand is that the piston should not a diameter more than 9 cm and less than 5 cm anything manufactured outside this limits is said to be a variation and the six sigma consultant should confirm that the pistons are manufactured within the said limits else if there is variation in the range then the company is not operating at 6 sigma level it is operating at a very low level.Ī company is operating at six sigma level implies that there are only 3.4 defects per million opportunities for example an airline company operating at six sigma level means that it loses only 3.4 baggage’s per million of the passenger it handles.īelow is Shown the Six Sigma Table and a graph explaining the meaning of various levels of Six Sigma. For example, if you want to find the average height of male population in India, you cannot bring the entire population of more than 2 billion into one room and measure their height for a scenario like this we take samples that is we pick up a sample (people) from each state and use statistical formulas to draw the inference about the average height of male population in a population which is more than 2 billion. Six Sigma is basically the application of Statistical formulas and Methods to eliminate defects, variation in a product or a process. ![]()
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