**About Fuzzy Logic:**

It is another tool that is gaining popularity in recent years. It is based on the observation that people make decisions based on imprecise and non-numerical information, fuzzy models or sets are mathematical means of representing vagueness and imprecise information, hence the term fuzzy. These models have the capability of recognising, representing, manipulating, interpreting, and utilising data and information that are vague and lack certainty.

**Fuzzy Logic Technique: **

FL is a technique for dealing with sources of imprecision and uncertainty that are non-statistical in nature. It is an innovative technology that enhances conventional system design with engineering expertise. FL is based on a complex mathematical body. However, its practical use is easy to learn.

FL is a true extension of convention logic. Therefore, anything that was built using conventional techniques can be built with the FL. However, in a number of cases, conventional solutions are simpler, faster and more efficient.

The basic idea behind the FL is quite simple. An exact rule or law cannot be defined for each possible problem. For these cases, humans approximate well solutions to the problems. This approximation is possibly due to the flexibility in the definition of the words that constitute the rules.

Hence, human logic is very flexible. FL simulates this human logic using a mathematical model. However, the nature of this simulation is different from that of ANNs. ANNs simulate the humans' nervous system and deals with the learning ability, whereas FL mainly deals with the decision making processes performed by humans based on linguistic terms.

**Fuzzy logic** is one of the powerful design techniques as with the other techniques like ANNs, FL systems have their own strengths and weaknesses. Fuzzy logic has been mainly suggested to handle fuzzy concepts, inexact information, and approximate reasoning in expert systems. In fuzzy logic, system behaviour can simply be described with a simple rule base containing many "if-then" rules.