Statistical Quality Control (SQC) is one of the most important application of statistical technique which plays a very important and significant role in the field of industry. These techniques are based on theory of probability and sampling and is extensively used in all types of industries such as aircraft, textile, automobile, petroleum, telephones, transportation, medicines, plastic goods, electrical equipment, etc. This SQC was introduced by W.A Shewhart of Bell Telephone Company of U.S.A in 1924. He introduced the idea of process control with the help of control charts. In the same year, Harold F. Dodge and Roming also of Bell Telephone Company, developed the idea of product control with the help of sampling inspection plans. Definition : SQC refers to the use of statistical methods in the monitoring and maintaining of the quality of products and services. Quality refers to the sum of attributes or properties that describes a product. These are gen...