Controlling helps in maintaining and improving quality. Controlling process has to start from the beginning, i.e., screening the quality of raw materials, then the process of conversion of raw materials into output and later on the inspection of final product. An effective quality control system will ultimately result in quality products, thereby increasing sales and profits, e.g., in Maruti Udyog Ltd., there is a strong control system which starts from the beginning, i.e., raw material to finished products, i.e., car which ensures in maintaining and improving quality of Maruti cars of various models.