Scatter diagram is the graphical presentation of relationship between two variables. Scatter diagram is an important tool out of 7 fundamental tools of quality control. Scatter diagram helps to confirm the degree of relationship between cause and effect. Here cause is an independent variable and effect is dependent variable. Scatter diagram is an important statistical tool to analyze the relationship of two variables. To create the scatter diagram take the values of independent variable on X-Axis where as the dependent variable is taken on Y-Axis. Plot the intersection points of X and Y on the graph. Draw a straight line passing through all the points. Analyze the pattern of the points. For different degree of relationship different pattern of scatter diagram is formed. If Y increases as X increases and data points are on the straight line then there is perfect positive correlation. If Y decreases with increase of X and data points are on the straight line then there is perfect negative correlation. But when data is scattered all over the graph then there is zero correlation.