What is a Frequency Histogram?
Like a histogram, frequency histograms show the spread or dispersion of data. Rather than sort the values into bins, a frequency histogram has one bin per value. Why Use a Histogram? Use a histogram to determine the distribution of measurable data and the capability (i.e., the level of performance the customers can consistently expect) of the process. A frequency histogram in Excel uses variable data to determine process capability. The customer’s upper specification (USL) and lower specification limits (LSL) determine how well the process delivers on customer requirements. In the chart above, there all measurements fall between the LSL and USL which means that the process always delivers on the customer’s requirements.