Modern Development of Quality: 

In the six decades since World War II ended, great leaders of quality have emerged. In addition to those previously mentioned, the following individuals have become famous for their contributions. Philip Crosby popularized his concept 'zero defects' and established the Crosby Quality College. Kaoru Ishikawa, created quality circles in Japan and invented the cause-and-effect diagram, after some time it is also known as the Ishikawa diagram. Armand Feigenbaum coined the phrase Total Quality Control and tirelessly promoted its core principles around the world. Japanese engineer Genichi Taguchi developed a unique system for designing industrial experiments. Eliyahu Goldratt created an improvisation system built around the principle of constraints. Other notable contributors to the profession include George Box, Eugene Grant, Jack Lancaster, Frank Grena, Richard Freund and Dorian Shannon. 

Kaizen, a Japanese word that roughly translates to improvement in English, means that workers make continuous, gradual improvements as they perform their routine work. Kaizen's goals include the elimination of waste (defined as activities that add cost but do not add value), timely delivery, scale production loads by quantity and type, standardized work, moving lines, precise sizing, equipment, and others. Its application is not limited to quality, but quality professionals have implemented it effectively. When done properly it humanizes the workplace, eliminates hard work (both mental and physical), and teaches people to use the scientific method and detect waste. 

Theory of constraints (TOC) has become a popular term for systems improvement programs. It is based on the principle that one—and often more than one—specific factor or element prevents or prevents the system from reaching a more desirable state of existence. Goldratt had an insight: Managing a complex system or organization can be both simpler and more effective, allowing managers to focus on a few specific areas, maximize performance in areas of key constraints, or increase constraints, allowing them to allowed to reduce by providing to create a barrier. This leads to the company's vision where constraint guides all strategic decisions. Goldratt's customers and students claim many great successes in applying their concepts. 'The Goal' novel authored by him and make the first famous business novel their journey that informed and entertained many thousands of managers and engineers as it showed the path to success by applying his concepts.