What is Toyota Production System?
Toyota production system is the production system that systematises the way of thinking and the management technique that improves a company’s competitiveness. Even though many people think the Toyota Production system could be applied to only mass production, it responds to the customer requirements in the small lot production of many products.
With the Toyota Production System principles, the best quality, the shortest lead time, and the lowest cost are expired through the thorough elimination of waste. In simple words, TPS is a philosophy of improving competitiveness as a company. Besides, it is a developing philosophy to enhance its effectiveness.
History of Toyota Production System.
At the beginning of the 20th century, as typified by the Ford Model T, the mass production era began in the United States. Then the moving assembly line production using conveyor lines was developed as the demand for that mass production. However, at that time in Japan, the small lot production of many products was demanded even though mass production wasn’t introduced. Plus, the market size in Japan was small, and it was difficult to make many kinds of products in small amounts.
Under these circumstances, people in the Toyota motor corporation tried to come up with a way to minimise the costs in the small lot production of many products. Finally, they came up with a production system to improve its competitiveness, and it is developed today’s Toyota Production System. Industrial engineers Taiichi Ohno and Eiji Toyoda are the primary predecessors known for the development of TPS.
Principles of Toyota Production System.
For a better understanding of this system, it is vital to have a thorough knowledge of the principles used in it. Originating from Jeffery K. Liker’s book, “the Toyota Way”, there are 14 Toyota Production System principles.
Here are those 14 Toyota Production System principles, and each of them is integral to the success of TPS.
Principle 1: Follow a long-term philosophy.
When taking management decisions in a company, one should base that on a long-term philosophy, even at the expense of short-term financial goals. It helps to avoid short-term decision-making. In an organisation, aligning everyone toward a common goal to grow should be prioritised over making money. It is what builds the foundation for other principles.
For the company, it means generating a greater sense of importance within the workforce than just going to work for money. Employees should believe that people are their greatest assets and should not be hollow. A good relationship should be built with the workforce along with trust, and the workforce committees should be supported and seen as assets, not objects of conflict.
Toyota production system thrives on building trust and having mutual respect with their customers. Therefore, one should accept their responsibilities and act self-reliant to improve the required skills to produce value and maintain that.
Principle 2: Work to create a continuous process flow.
One of the main ways to achieve a high value-added continuous flow is redesigning the work process. Try to avoid waiting time for any work project(one of the 8 wastes of Lean Management). The traditional approach to manufacturing is to group similar machines and similarly skilled people resulting in units of excellence or departments of a similar function. It aims to immediately bring problems to the surface and keep the unit price to a minimum. It also gives apparent flexibility as employees can change around work.
For example, consider a traditional manufacturing operation with three manufacturing machine sales run in batch production in a welding department. To make a product, it has to go through each of the machines in order and the cycle time for each machine is 1 minute. If the order is for 10 parts, firstly, those 10 parts will have to be machined in machine 1, and it will take 10 minutes to complete the batch. Then it will be transferred to machine 2, and it will take further 10 minutes to complete. Then it will be forwarded to machine 3, where it will be finished off in another 10 minutes. The total time to complete would be 30 minutes. The first part will come through after 21 minutes (10+10+1).
Now consider the same product goes through a lean process where we have a one-piece flow. The first piece will straight away go through machine 1, then machine 2, and lastly, machine 3 without being batched. The total time to complete one part is 3 minutes. We will then get a completed part off the line every minute following. Then a total of 10 parts will be completed in a total of 12 minutes.
This clearly demonstrates the benefit of following the continuous flow. As we know, the objective of Lean is to provide what the customer wants when they want it in the quantity that is required. It takes a considerable amount of time, effort, and change to be undertaken to create a reliable continuous flow.
Here are some activities required to move to a continuous process flow.
- Creating excellence in workplace organisation.
- Standardising processes that are developed around simple machines.
- Having well-maintained reliable systems.
- Having a well-planned layout.
- Proper training and communication between employees.
- JIT processes.
- Kaizen activity programs.
Principle 3: Use the “Pull” system to avoid overproduction.
In traditional manufacturing systems, machines run as fast as possible for as long as possible because they are operated to maximise output. They are generally accounts-driven, and the focus is to gain payback and return on the capital equipment investment. On any other equipment than the bottleneck process, this will only generate an inventory.
We fill our cars as we need fuel. If we dispense the same quantity of fuel to our car each week without any indication of the requirement, it will either overfill and spill, or we will be running out of fuel depending on the car’s usage. The car has visual indicators to help us control our fuel requirements.
The needle indicator shows fuel level status and a visual control light to prompt us to action when required. Working to the prompting signals for refuelling is analogous to pull systems in manufacturing. Systems were developed to signal demand in manufacturing with the development of the Toyota production system. The signals were based on card systems or by using empty parts bins or carts. These systems were called kanbans.
Kanban refers to a signal device of some sort to trigger production to take place in a pull system. A “Pull” process is a system of manufacturing in which each production process withdraws from the proceeding process. A “Pull” process requires trigger signals for control, and this is provided through the application of kanbans.
For example, consider a supermarket shelf that has products on it with cards attached to each product. When a customer takes a product, they take the card with it. The cards have product identifier details on them relating to the products to which they are attached, and when the customer gets the details, the checkout operator takes the card off each of the products.
The cards are then sent to the warehouse so replacement products can be picked to refill the shelves. This means that replenishment of the shelves will not only be timely, but the correct products and quantities will be delivered to the shelving area. This will eliminate waste. If the card system were not used, it would be difficult to determine what was required in the shelving area.
Staff would have to be employed to check and make lists, and the data would always have inaccuracies because a product is constantly being taken off the shelf. Manufacturing kanbans are used in the same way. It may be cards or empty boxes that are returned upstream to trigger the replenishment downstream. Kanban was the method developed by TPS to generate the pull system.
Principle 4: Level out the workload (heijunka).
Stabilising the system and creating an evenness or levelling out the work schedule is known as “Heijunka” by TPS. Eliminating waste plays an important role in successful Lean management. Therefore, eliminating unnecessary workload on people and equipment and banishing uneven production schedules is just as vital in an organisation. Instead of working on projects in batches, companies should apply this principle of attempting to level out the workload of all kinds of processes.
Principle 5: Establish a constructive company culture.
The foundation for “building in” quality is Jidoka. It is known as “automation with a human touch” or autonomation. The concept of jidoka provides capable machines that detect and flag abnormal conditions in manufacturing in any company allowing process operators to address the problems more quickly.
Using all the available modern quality assurance methods and building types of equipment that are capable of detecting problems and putting an end to them develops a company culture. Further developing a visual system that can alert team or project leaders to signal that a machine or process needs assistance would also help to establish a constructive company culture in the company. Construct support systems that assist the company with solving problems just as they occur and take countermeasures. This will help create quality products the first time around.
Principle 6: Standardised workplace.
Standardised workplace tasks aim to improve and empower employees in an organisation continuously. Therefore, an organisation should always use stable methods to maintain predictability and regular output at a regular times. Standardise today’s best practices to capture accumulated learning about processes. Standardised workplace tasks give employees a reliable job method; moreover, it helps in uplifting the continuous improvement while banishing other uncertainties.
Principle 7: Use Visual Control.
In an organisation, designing a simple visual system at the workplace supports a company’s flow and pull systems. Plus, visual tools create a more organised workspace by alerting the workforce about hazardous situations and showing distinct operation processes. To abide by this Toyota production system principle, try avoiding using a computer screen as it distracts the worker’s focus away from the workplace and reduces the waste of resources. For example, reduce the reports to one piece of paper whenever possible.
Principle 8: Use only reliable, thoroughly tested technology.
Companies should use technology to support people, not to replace people. Therefore, manually working out the process before adding technology is a smart way. Companies must conduct true tests before adopting new technology in business processes, manufacturing systems, or products, as new technologies are unreliable and difficult to standardise most of the time.
Then after testing, reject those that might disrupt the stability, reliability, and predictability of work processes. Modify other technologies not to conflict with your company culture. Further, implement technologies that have been proven in trials and can work to improve the flow of processes.
Principle 9: Grow leaders to live and teach the philosophy.
A leader is a role model and someone who can promisingly encourage the established company culture to thrive. Therefore, try building leaders within the organisation rather than buying them from outside the organisation. Then, teach those leaders to live and pass on the Toyota Production System principles and its philosophy.
Principle 10: Develop exceptional people and teams.
It is important to create a stable culture where the values and beliefs of the company are lived out over many years. For that, train individuals and teams to work within the corporate philosophy and aim to achieve exceptional results. Empowerment in any company occurs when people use the company’s tools to enhance the company. To improve quality and productivity, try using cross-functional teams. Plus, teach individuals to work together as teams toward common goals.
Principle 11: Respect the extended network of partners and suppliers.
Respect for all suppliers and stakeholders should be maintained as they belong to the extended network of your business. Challenging them would help them to grow and develop as a company. Moreover, it shows that you value them.
Principle 12: Go and see for yourself to thoroughly understand the situation.
In an organisation, managers and executives to employees at the lower level of the hierarchy should solve problems and improve processes by going to the source to personally observe and verify data rather than theorising based on a superficial understanding of the situation.
Principle 13: Make decisions slowly by consensus, and implement them rapidly.
Nemawashi is the process of discussing problems, figuring out potential solutions with those who will be affected, gathering opinions, and finally choosing a path forward. Even though this consensus process is time–consuming, it broadens the search for solutions. Therefore, after the final decision, it should be implemented as soon as possible.
Principle 14: Reflect regularly (hansei) and improve continuously (Kaizen).
The final Toyota Production System principle is the relentless reflection on the process. Following Lean techniques such as Kaizen, Kanban, Shingo method, etc., will only benefit the business to thrive more through its continuous improvements.
Toyota Production System is a production system that gathers the wisdom and ingenuity to provide expensive and high-quality products in an environment where mass production cannot be introduced. Toyota production system principles help to unfold the riddle of this production system, and those Toyota production system principles benefit society as a whole.