Given plant data of a specific operating condition, the following steps could be used to construct a histogram:

• From the data it would be important to determine the range of values occurring in the data set for the selected variable.
• The range of data values would then be subdivided into appropriately sized bands.   The width of each band should represent a meaningful change to product quality, profit, safety or some key goal of plant operation.
• Then from the data, determine what percentage of the total data occuring in each band.
• The final step would be to plot the frequency fraction in each band over the variable value.