The analysis of data is best handled by the use of graphics and charts. Nearly all Statistical Process Control or Corrective Action Steps require the use of simple graphs or charts. The purpose of this module is to introduce the basic types and methodology for making graphs and charts. Qualities of a Good Graph Summarizes the data collected. The line graph illustrates how a part or process characteristic changes over time.
Line graphs are the simplest graph to construct and use.
The X axis is usually used to record the time-frame or sequence of the data being plotted. The Y axis is usually used to note the measured value or effect. The origin, or zero point, is the point where the two axes meet. The scale determines how the data appear on the graph. The first step is to collect accurate and complete data.