**1. Introduction**

After the Second World War, the associated powers found that the nature of the Japanese telephone system was incredibly poor and absolutely unacceptable for long term communication purposes. To improve the system, it is recommended to establishing research facilities in order to develop a state-of-the-art communication system. The Japanese founded the Electrical Communication Laboratories (ECL) with Dr. Genichi Taguchi in charge of improving R&D efficiency and improving product quality. He observed that a great deal of time and money was expended on engineering experimentation and testing [1]. Taguchi seen quality improvement as a progressing exertion. He continually strived to reduce the variation around the target value. To accomplish this, Taguchi designed experiments using specially constructed tables known as OA. The use of these tables makes the design of experiments very easy and consistent [2]. Design of Experiments (DOE) is powerful statistical technique presented by R. A. Fisher in England during the 1920s to study the impact of numerous factors at the same time. In his initial applications, Fisher needed to discover how much rain, water, fertilizer, sunshine, etc. are expected to deliver the best yield. Since that time, much improvement of the system has occurred in the scholarly condition yet helped create numerous applications on the generation floor [3]. In late 1940s Dr. Genechi Taguchi of Electronic Control Laboratory in Japan, carried out significant research with DOE techniques. He spent extensive exertion to make this trial procedure easier to use and to improve the quality of manufactured products. Dr. Taguchi's standardized version of DOE, popularly known as the Taguchi method or Taguchi approach, was introduced in the USA in the early 1980s. Today it is one of best optimization techniques used by manufacturing industry. The DOE using the Taguchi approach can monetarily satisfy the needs of problem-solving and product/process design in optimization projects. By learning and applying this procedure, specialists, researchers, and scientists can essentially decrease the time required for exploratory examinations [4].
