Using cause-effect graphing

In the preceding example, application support depended on which operating system and web browser you were using. This can be visually presented in a cause-and-effect graph, which lets you visually display relationships between different variables and specific outcomes. These use standard logic operators of AND, OR, and NOT. The following diagram displays an AND relationship:

Figure 5.1 – AND relationship between two variables and an effect

These diagrams use traditional symbols representing the logical operators:

Figure 5.2 – OR relationship between two variables and an effect

The AND and OR operators can take two or more inputs and have their usual truth table outputs. The following diagram displays a NOT relationship:

Figure 5.3 – NOT relationship between variable A and an effect

Using this technique, you can map complex relationships between inputs and outputs...