Pareto Graphs

A pareto graph is graph that is specifically designed for identifying sources of defects. In a pareto graph, a series of bars identifies different sources of defects. They are arranged by value, from the greatest number to the lowest number. A line shows the percentage of the cumulative values of the bars, to the total values of all the bars in the graph. The line always ends at 100 percent.

Pareto graphs are dual-Y graphs. The Y1-axis corresponds to values that the bars represent. The Y2-axis corresponds to the cumulative percentage values.

Standard use of a pareto graph

You use pareto graphs to identify types and sources of defects, so that you can focus corrective action on the biggest sources of problems.

Available varieties of pareto graphs

Only one variety of pareto graph is available. The constant is PARETO.

Graph properties for pareto graphs

The following properties of the Graph object affect pareto graphs:

Data structure of a pareto graph

The following figure shows the data structure of a pareto graph. In this graph, each of five bars shows a cause of a traffic fatality. The first two causes, failure to maintain lane and high speed, account for 70 percent of the total fatalities.

Sample pareto graph

The data structure for bar graphs is as follows:

The line in a pareto graph is calculated from the data values that you supply to the graph.

Data guidelines for pareto graphs

Pareto graph data has the following guidelines:

Handling Problems in Graph Data
Specifying Data for a Graph