Fuzzy logic is an heuristic method and is well-suited for systems that require the ability to handle vague data and/or model imprecise reasoning procedures. A fuzzy-logic model uses IF-THEN rules in conjuction with logical operators to form the rule base of the system and membership functions to map identified inputs of the system to membership values from 0 to 1. The process of defuzzification coverts the fuzzy value obtained from fuzzification process into a crisp value.