CHALLENGES OF INTELLIGENT QUALITY MANAGEMENT
How quality management changed in industrial production and manufacturing
22 May 2019: Edgar Dietrich
History of quality management systems
From quality control to operator self-inspection
With the introduction of mass production, as implemented into the automotive industry by Henry Ford, the precision of components and sub-assemblies assumed a greater significance in the assembly process. When parts could not be assembled or proved to be defective, the entire assembly line had to be stopped or operators had to access this very part to rework it. To avoid this kind of situation, quality control became part of the production process. This development formed the foundation of a new department called “quality control” or “quality assurance”. This department did not depend on manufacturing, production or assembly at all and was responsible for the final release of a product after the final inspection. This responsibility, however, was frequently bound to provoke conflicts between product manufacturers and quality managers. Even though 100% inspections reduced the margin of error, they increased the required effort considerably.
As mass production started to prevail and quality demands on products continued to rise, sampling inspections helped reduce quality costs. This type of inspection is based on various procedures worldwide. In the 1930s, it was Walter Shewhart who introduced Shewhart quality control charts – named after him – successfully at the Bell Telephone Laboratories, his employer. Even though his procedures brought about a revolution in statistics at that time and attracted increasing interest, only few companies applied them in an increasingly industrial production and manufacturing environment.
As manufacturers broadened their vertical range of manufacture, outsourced the production of single components and received these products “just in time” from their suppliers, quality demands rose even further. This trend particularly affected the automotive industry.
It was again the Ford Motor Company changing the issue of quality control considerably at the beginning of the 1980s. This was due to the introduction of the quality management system Q-101 applying to both, Ford internally and to their suppliers. This system established quality control charts as developed by Shewhart and capability indices helping to assess the quality of machines, processes and products.
In addition, companies started to replace the independent function of quality control by the operator self-inspection. From then on, the respective staff of the production and manufacturing division bore the responsibility for the quality of machines, processes and products. Companies thus no longer needed “quality control” departments and the associated name disappeared, too. “Quality assurance” and “quality management” were the new terms used in this context and the selection of methods and procedures they involved became known as a “quality management system”.
Big Three established uniform rules in the automotive industry
In 1994, Chrysler, General Motors and Ford (also referred to as the Big Three) issued a joint quality management system in the US - QS-9000 Quality System Requirements. To a wide extent, it was a kind of sequel to Ford’s Q-101 quality management system but included some improvements...