In the process of knowledge acquisition, knowledge is acquired through some phases of knowledge acquiring. For a individual device like air conditioner, a proper literature study is performed in first phase. Then in second phase, a set of questionnaire is prepared. To improve the quality and magnitude of questionnaire, feasible study or pre-testing is performed in next stage. In fourth stage, modification in the set of questionnaire is performed. After the completion of
modification process, the fifth stage builds an interface with human experts or specialist engineers to conduct new & fresh surveys. In sixth stage, the results of received information is
confirmed with human experts. In next stage knowledge is extracted from the gathered and retrieved data and then inserted into a knowledge base, which is arranged in the form of decision tree. To form the decision tree a forward chaining method is used. Above discussed process is depicted