Walter Shewhart was an outstanding statistician, physicist, and engineer of his time. He made significant contribution to what we know today as statistical quality control. Shewhart is considered to be the father of statistical process control (SPC) – a quality control methodology that relies on mapping production processes on diagrams which are commonly referred as Shewhart control charts.
Walter A. Shewhart was born on the 18th of March 1891, in New Canton, Illinois. He first studied at the University of Illinois, before attending the University of California, in Berkley, where he received the doctorate in physics in 1917at the age of 26.
His work primarily focused on the quality industrial sector. One of his first jobs was within the Bell Telephone Company. Although this communication company held the monopoly on the telephone market, it was Bell Telephone’s intention to impress the government regulators to maintain good standing. Walter Shewhart was tasked to work in this direction and to bring considerable improvements on how the existent carbon transmitters managed to transmit the sound of the voice. A higher clarity was desired. Walter Shewhart used the statistical methods he developed on his own to achieve improvement. His methods were later used in mass production. By 1918, Shewhart was already a member of the Inspection Engineering Department, within the Western Electric Company. Here, industrial quality was a function of only to two primary operations: verification of the finished product and removal of any noticed defects.
On the 16th of May 1924, this entire system was changed. Dr. Walter Shewhart developed one-page memorandum which included a diagram. It is what we all know today as a control chart widely used in the statistical quality control. The control chart, also known as the Shewhart chart, is a record of a process behavior data, used for assessing a business or manufacturing process.. With control chart application Walter Shewhart strived to achieve reducing variations found during a manufacturing process. He identified two types of variation: common cause and special cause variation. The Shewhart control chart has since been used to distinguish
between the two types of variations. Walter Shewhart aimed at bringing the manufacturing processes into a state of statistical control, where only common (chance) cause variation existed and special cause variation (which caused the most number of defects) was eliminated or significantly reduced. If this cause was held under control, through the entire process, then the output could be predicted, leading to a better management of the process, from an economic point of view. The control charts developed by Walter Shewhart were used by the American Society for Testing and Materials and even recommended for production optimization during the Second World War. After the 1930s, Walter A. Shewhart became more interested in statistical inference .His entire work much different from that of his colleagues. The courage he had to think outside the box led him to develop systems that are used even in present days. Walter A. Shewhart is a founding member and fellow of many statistical and mathematical institutes and associations throughout the country.