1 materials (components, components, suppliers, consumers)
Two methods (procedure, policy, finance)
3 Environment (noise level, humidity, temperature, light intensity)
4 people (training, experience, skills, attitude)
5 Equipment (technology, differences, tools, fixtures)
6 Measurement (calculation, instruments, measuring tools, testing)
Six Sigma thinks according to the logic of process model when solving problems. Take the problem y to be solved as the process output; X, the cause of the problem, is considered as process input. The reason is hidden in the process.
From the improvement point of view, because the relationship between input and output can be expressed by Y=F(X), the fluctuation of process input factor X leads to the fluctuation of output Y. Process input includes personnel, methods, environment, equipment, measurement, raw materials and so on. The above inputs are changing all the time, and the changes of these inputs cumulatively act on the output, resulting in fluctuations or even anomalies in the output.
Therefore, the above inputs are all sources of variation in the process. When analyzing and solving problems, we must select the key input factors from the complex changing environment. This process is called multivariate analysis.