Definition
The frequency pattern of each value in a set of data (center, spread, shape), such as Normal Distribution and Poisson distribution.
In detail
Distribution (statistical) refers to the statistical distribution shape of data observations, such as normal distribution, Poisson distribution, etc. It describes the central tendency, dispersion, and shape of data, and is the foundation of statistical analysis. In quality management, understanding distribution helps assess process capability and identify anomalies. Compared to histograms, distribution is a theoretical model, while histograms are data displays; compared to control charts, distribution focuses on overall shape rather than time order. Outputs typically include distribution fitting results and parameter estimates.
Example in practice
When measuring part dimensions, 100 data points are collected, and a histogram reveals a bimodal distribution, suggesting two different production batches or equipment. Further analysis confirms that raw materials from different suppliers are the cause, leading to an adjustment in procurement strategy.