Improved cognitive modelling: Fuzzy systems allow the encoding of knowledge in a form that reflects the way experts think about a complex problem. They usually think in such imprecise terms as high and low, fast and slow, heavy and light. In order to build conventional rules, we need to define the crisp boundaries for these terms by breaking down the expertise into fragments. This fragmentation leads to the poor performance of conventional expert systems when they deal with complex problems. In contrast, fuzzy expert systems model imprecise information, capturing expertise similar to the way it is represented in the expert mind, and thus improve cognitive modelling of the problem.