While it is important to collect accurate data, data is useless in itself. The presentation of data must foster understanding of problems and suggest solutions. Workers may put collected data into control charts. The act of consistently recording data related to product specifications has a consistent, positive effect on quality. Generally, the ordinate shows process variables, and the abscissa shows time intervals.
R represents the range of a sub-group, x, the average.
A c chart shows data for products of constant size. A u chart shows data for products of varying size. One common presentation is the Histogram. This can help visualize the characteristics of a process with clarity. Histograms can reveal the central tendency of a process.