After we define our linguistic variables for our input and output, we need to define the relationship between the input and output. This is where rules come to play. They are fuzzy rules as they deal with the linguistic variables and their values (degree of membership).

Rules define the interaction between our input variables to produce the output. Here we have three simple rules for our example:

1. If project funding is adequate or project staffing is small then risk is low.
2. If project funding is marginal and project staffing is large then risk is normal.
3. If project funding is inadequate then risk is high.