Shigeo Shingo and His Contributions to Total Quality Control

Dr. Shigeo Shingo is a name highly respected amongst engineers and the scores of people currently associated with quality control across industries. He is said to have attained Kaizen, the Japanese word associated with improvement. To be more precise, the concept in business it refers to the perfect synergy between all the activities of an organization. This may be from the level of the CEO himself down to the assembly line workers on the floors of thousands of factories across the world.

Early Life, Work, and Contributions

Dr. Shingo earned a degree in mechanical engineering at the Yamanashi Technical College in 1930 and soon after, gained employment at the Taipei Railway Factory. Whilst there, he became interested in quality improvement initiatives and scientific management across the company.

By 1946, he was working at the Japan Management Association Technical Conference where he began looking into productivity problems associated with the plant. He began his research in early 1951 on Statistical Quality Control, after which Toyota leveraged his project and work. After achieving excellent results with his theories, they hired him as a consultant.

By 1955 Dr. Shingo was already leading the industrial engineering and factory improvement training team at the Toyota Motor Corporation. In 1956, he led a three-year study on shipbuilding at Mitsubishi Shipbuilding and came up with a system that halved the production time. He is also credited with the completion of the SMED, or single-minute-exchange of die method which is a type of Lean manufacturing method. He achieved zero quality defects by leveraging the improved version of SMED.

His principles still form the backbone of what quality control is all about to this day.

Shingo’s contributions to Quality Control

During his lifetime Shingo contributed quite a bit to further quality control processes in the industry. His teachings can be bucketed into three main topics

1. Just In Time (JIT)
2. Single Minute Exchange of Dies (SMED)
3. Zero Quality Control

Just In Time (JIT): This concept in quality control was developed mainly by Dr. Shingo in collaboration with Mr. Taichii Ohno from the Toyota days. To summarize the concept, this is a planned way to eliminate all waste along with continuous improvement in productivity. It encompasses a perfect synergy of all activities related to manufacturing a particular product. A few primary elements of JIT would be:

1. To have only the required amount of inventory at a given time
2. Improve quality to have zero defects
3. To reduce lead time by reducing setup times
4. Optimize queue lengths and lot sizes

The key thing to remember is to accomplish the above at minimum costs. If a company were to apply the above tenets, they would be able to cut costs in an optimized and effective manner. Also, the use of statistical methods helps ensure that the product is met with desired results consistently.

Single Minute Exchange of Dies (SMED): Dr. Shigeo Shingo, as part of JIT, also helped advance and develop the existing SMED process. The basic tenets which drove the study were:

1. Reduce setup time of dies
2. Smaller batch sizes for parts

The above becomes very beneficial to companies looking to cut costs as it allows the manufacturing system to adjust quickly to changes in design with a very little cost to the company. In addition to the cost benefits, this new and improved SMED process also allowed for zero defects, higher machine efficiency, and in turn results in a high production rate.

His brilliance lay in the way he approached the SMED process. His idea was to isolate and identify the time required for setup into two main entities: internal time and external time. Many companies that have stamping operations have found great success using his methods.

Zero Quality Control (ZQC): Dr. Shingo’s ZQC method are based on a few principles as stated below

1. Quality inspections should be done at the source of the process instead of routine sampling inspections
2. Quick feedback from the quality checks and self-checks
3. Poka-yoke designed manufacturing devices

His basic idea was to target the defect at its root cause to eliminate it from the process effectively. He firmly believed that in addition to statistical methods, sound manufacturing processes would go a long way in eliminating defects altogether.

Conclusion

Dr. Shigeo Shingo was perhaps one of the greatest contributors to the study of total quality management and modern manufacturing methods. Although his name isn’t as well known as some others in this space, his principles have slowly but gradually formed the backbone to manufacturing processes in Asia and South East Asia.