The period of 1920 to 1940 saw the next phase of qual­ity. This phase was so-called ‘Inspection Quality Control’. With more complicated prod­ucts and processes it became impossible for to keep close watch over individual stages of operation. Inspectors were assigned to check the quality of a product after processing. Individual product standards were set, and any discrepancies between standard and actual product features was reported. Defective items were set aside as scrap, and few items with minor defects are reworked to meet the specified standard or specification. In this period, statistical process control aspects of quality were also popularized, and gained widespread application in industries.  In 1924, Wal­ter A. Shewhart of Bell Telephone Laboratories introduced the concept of statisti­cal charts to monitor variability of product characteristics.  These charts were called control charts. In the latter half of 1920s, H. F. Dodge and H. G. Romig, also from Bell Telephone Laboratories, proposed acceptance sam­pling plans for inspection. These plans substituted the concept of 100 percent inspection. During 1930’s application of acceptance sampling plans was in full flow in industries. In 1929, Walter Shewhart with the help of American Society for Testing Materials (ASTM), American Society of Mechanical Engineers (ASME), American Statistical Association (ASA), and Institute of Mathematical Statistics (IMS) created the joint committee for the development of statistical techniques for application in engineering industries.