Toyota Machine Work Study - Machine Improvement in Toyota Production System (TPS)

Prof. KV.S.S. Narayana Rao, NITIE

Jidoka (A Pillar of TPS) = Automation - Machine Work Study - Machine Improvement in Toyota Production System (TPS) - Improvement of Men and Machines

The Toyota Production System (TPS) is a global benchmark for operational excellence. In Toyota plants, workers constantly squeeze out waste and boost productivity. The famed standard work chart displayed near the machine  is strictly audited and regularly updated as each process is improved. It is industrial engineering. It is continuous engineering improvement based on the experience and data generated in the operations. In Toyota Production System industrial engineering is done by the work groups also on the shop floor and it is they who own the standard work.  The work of industrial engineers and production engineers is not highlighted by the US and Western Scholars who studied the special nature of TPS. Significant inputs from industrial engineers form part of the TPS improvement. Shigeo Shingo is the most prominent industrial engineer who contributed to the development of TPS.

Industrial Engineering of Machines by Toyota

Shigeo Shingo specially highlighted equipment planning, purchase and improvement practices of Toyota. There are thousands of machines at Toyota and each one has been improved to suit the specific needs of the company. Expensive, special-purpose equipment or robotics are not considered good investments. Less expensive machines are bought and further improved inside Toyota to meet the special needs of the plant. Thus industrial engineering of machines, redesigning the machines based on the present industry data of shop floor data is practiced in Toyota.

What is Toyota Doing now in Automation?

Toyota’s TPS gurus preach a cautious approach to automation. But, Toyota is not afraid of automation. One of its pillars, Jidoka is based on automation only.  In paint shop, robots are everywhere. In  the body shop  robots weld steel panels together. The shop that stamps those steel panels is also heavily automated. Engines and transmissions are full of machined parts produced by banks of CNC machines, with automation moving parts from one station to the next. 

One Toyota mantra is simple, slim and flexible: It is their vision for manufacturing processes. It has an army of production engineers who design and build its own automated systems. Toyota had its version of too much  automation decades ago. Built in 1979, Toyota’s plant in Tajara, Japan,  But when the vehicles did not sell that well due to the high cost of automation, the plant lost money. The high fixed cost resulted in too little flexibility to adjust to market demand. This lesson was painfully learned  The countermeasure is a policy that new plants must have the break-even of 70 percent of planned capacity. If a plant was running at full capacity at some time and sales dropped by 30 percent, the plant should at least break even. Simple, slim and flexible mantra gave a  formal directive for the company's production system designers.

Ohno’s teaching always started with a challenge to accomplish something that at first seemed impossible. The student was asked to go to the shop and observe the machine and the process  to study the current method  and develop a deep understanding under Ohno’s watchful eye. When the understanding was deep enough, the student was asked to come with a change and try it. The student has to come with an engineering idea that can be implemented quickly and the result can be assessed and he can learn from the experiment. Ohno relentlessly challenged the student to continue to experiment and more deeply understand the process.The student thus is engaged in thinking deeply and experiment again and again, until the challenge was met with appropriate guidance from Ohno.

Managers, engineers and operators need to learn how to use the machine and the materials and their five senses to create a good part at a reasonable price according to Ohno. Then intelligent automation has to be developed to decrease the cost of changing the shape or form of the material and also to reduce as much as possible any transportation or movement. This means managers, engineers, and operators have to get inside the equipment and redesign it to eliminate waste and this  work has to be done by people in the plant. 

Mitsuru Kawai is a board member of Toyota now. He joined as a blue collar worker. . He spent most of his career in Toyota’s Honsha (headquarters) plant, which machined and forged metal transmission parts. He got personal guidance from Taiichi Ohno, father of the Toyota Production System, in creating good methods change (kaizen).  

Kawai became expert at improving the equipment. There is a problem now.  The younger people had not experienced the way automation evolved from manual work that transition. They know only that if  you push a red button and  part comes out. Kawai has to make managers and engineers with  skills to get inside the machine and learn how to see waste inside automated processes and machines. His proposition is that  managers, engineers and production operators have  develop four skills: Visualize production; develop explicit knowledge of the process; standardize the knowledge; and develop intelligent automation through improvement of machines .To learn the four skills, engineers had to learn to do the actual processes manually. To develop people with these skills, Kawai directed that all team members, engineers and managers to perform the forging and machining jobs manually till they learn the skills to the adequate level. A manual assembly line was also created so that each employee still experiences the traditional method of improving manual work further and engineering new tools and work holding fixtures and improve the process further and further.  A real manual assembly is in place for it and it produces saleable items of products that are selling small volumes. This is called it the “TPS basic learning line.” 

As a part of  learning to improve the automated processes and the machine, each learner is given  one piece of  equipment. He has  to hand-draw in detail everything that happened to the part, second by second, as it was moved, oriented and transformed. The managers and engineers with knowledge of the machine are there as mentors to ask the tough questions as well as answer questions by equipment learners. 

A similar learning organization is created called "super-skill line." Its purpose  is to make automation better. it. This pilot line creates a smooth flow of work, which then informs automation team. The super-skill line rapidly tests ideas without using inexpensive automation elements or mechanism. This  manual line makes it clear where automation can help.  Ideas migrate from the manual 

line to the plant’s high-speed lines. 

Toyota considers  three questions regarding automation:

1a. Are our plants without new, fancy automation working in the direction of one-piece flow and continually solving problems every day?
1b. Does inventory build up? Do defects, equipment problems and bottlenecks interrupt production and can they be solved using new automation possibilities and equipment?

2. Have we developed our people to be highly skilled in improving the present automated equipment and give ideas regarding future automation?

3. Do we have a disciplined workforce and the internal capability to maintain and improve the  equipment we bring into the factory?

Industry 4.0 can be  a wonderful excuse to ignore difficult and  entrenched problems by simply spending money on new equipment. But the problems will come back and make investments a burden. Viewing new technology as the solution ignoring existing process problems comes with 

serious problems.

Installing new equipment with fancy sensors tied to the internet happens because it is the latest craze, without identification of specific opportunities where specific technologies will add value. If the capability of the current  process is not understood,  the business case compares an automated factory to a mediocre operation with older technology.

The internet world was created by information technology lovers who  see the world through computerization view point and design. Some features  work, and others don’t and productivity effects are uneven. They need to be carefully designed, maintained and, at  Toyota, they need to be continually improved by people who understand how things work and how to make them work better. Ohno’s key concept of working at the shop floor, understanding the process and improving it by eliminating waste  kept Toyota's operations managers and industrial engineers  knee deep in reality. Industry 4.0, if not analyzed thoughtfully from manufacturing and industrial engineering point of view, threatens to add waste to the systems being designed and sold by the new enthusiasts and  take us further and further away from reality of the current shop floor.

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The cost of upkeep and maintenance are to be understood.  Maintenance cannot be automated.  Maintenance,  preventative and or even predictive, requires people to use all their senses to deeply understand the equipment. In Toyota, people say their equipment's worst shape is when it was first bought and installed.  . Excellent maintenance and improvement will make the equipment better over a period of time. The lessons of Toyota Production System have taught us that there is no end to human creativity, and even operators unleash their creativity to achieve increasing levels of operational performance in manual work as well as machine work. The new technology set of industry 4.0 provides us an the opportunity for designing amazing systems and make human life more comfortable for all and especially make things more better for poor and extremely poor persons in the society. Industrial managers, industrial engineers and operators have to become  disciplined, understanding the process thoroughly and become  creative people living on the shop floor to maintain and improve the equipment. They have to be more adaptable than machines to work them for maximum productivity and improve them further.


References

Jidoka of machinery - From History of Toyota

https://books.google.co.in/books?id=7WfSBwAAQBAJ&pg=PA183#v=onepage&q&f=false

Don’t count humans out, Jeffrey K. Liker, ISE Magazine, 2018.

Ud 16.10.2021

Pub 14.11.2019