At its recently held monozukuri (‘the art of making things’) workshop, Kazuaki Shingo, chief production officer Toyota Motor Corporation, explained the transformative approach to car-making the company is taking by leveraging Toyota’s unique human-centred approach to manufacturing.
Human-Centred Approach To Manufacturing
Toyota Motor Corporation inherited its human-centred approach to manufacturing from its founder, Kiichiro Toyoda: “we make things for the benefit of others”. From this philosophy was born the unique Toyota Production System (TPS), which aims to maximise the use of human resources to shorten lead-times and constantly refine jidoka (‘automation with a human touch’). TPS focuses on shorter lead times, which then makes it easier to identify issues and stimulate kaizen (‘continuous improvement’). This style of monozukuri is unique to Toyota and forms the basis of the company’s approach to accelerating the future of car manufacturing.
Evolving The Industry Respected Toyota Manufacturing Philosophy
Toyota believes that to deliver the ‘future of car manufacturing’ it is necessary to evolve the philosophy of monozukuri by blending ever-evolving human-centred best practices with digital tools and innovative technologies.
Since its foundation, Toyota has encouraged its production line members to gather on the shop floor to share their skills, ingenuity and wisdom to help create and mass-produce new products. This process continues today and is further supported by the establishment of a ‘start up studio’ where members can share learning to respond quickly to the challenge of new manufacturing processes, and ideas that can be quickly materialised towards prototype development and mass production technology.
Ongoing Importance of Takumi Skill Base
Toyota employs many highly skilled manufacturing professionals called Takumi. Their delicate work realises high-quality product finishing at a level that robots cannot yet achieve. Since many Takumi skills are based on tacit hands-on knowledge, passing them on to the next generation poses a challenge. Toyota is using digital technology to visualise the practical skills of craftspeople in an easy-to-understand way for next generation and it has the potential to automate these skills in the future.
This approach is already leading to new manufacturing and processing methods. For example, Takumi engineers are now able to use advanced processing technologies to realise highly unique designs which were previously considered too difficult to produce. An example is the world’s first bumper processing technology that successfully applies incremental moulding technology to plastic resin materials on the new Lexus LC.
Mixed-Model Production Lines
It is not unusual for Toyota to produce multiple models on one production line. Still, at its Motomachi Plant, the level of complexity is multiplied by combining different body types with multiple powertrains. This degree of variation requires a unique level of production agility, which places a greater level of challenge on workers. Reflecting the TPS principle of ‘making another’s job easier’, the identification of higher level kaizen techniques has led to the development of multi-skilled workers whose experience is being used to tackle complex future manufacturing challenges
Digital Tools For The Future Of Car Manufacturing
Toyota is using digital tools to shorten the lead times of equipment manufacturing and improve the productivity of existing facilities. To shorten the lead-time of installing and commissioning new production facilities, digital 3D models are being used to identify unanticipated defects and difficulties in manufacturing equipment that might otherwise cause longer lead times involving redesigning and remanufacturing.
Furthermore, using a digital twin halves the lead time for production preparation as potential defects in the process can be identified in advance, thereby enabling Toyota front-line workers to apply their knowledge and experience at the equipment design stage.
Toyota is also using digital 3D models of its existing facilities to improve productivity with reduced lead times for implantation. This approach has also led to additional automated processes.
Innovative Technologies For The Future Of Car Manufacturing
Innovative technologies are being implemented to improve efficiency and productivity. Improving efficiency, increasing productivity and shortening lead times are what TPS does best, and Toyota is identifying and implementing quick wins to optimise the mass production of next-generation battery electric vehicles.
The goal is to halve the number of processes and plant investment with the new modular gigacast technology and with the self-propelling production line. Toyota’s innovative Gigacast technology features aluminium die-casting which eliminates many parts & processes. It is designed as a three-part modular structure which has the benefit of allowing manufacturing and assembly work to be performed in an open environment. The three-part modular architecture also allows for greater variety in the types of vehicles to be designed and produced.
Gigacast technology requires the periodic replacement of casting moulds, which typically takes around 24 hours. However, Toyota has been able to significantly reduce this changeover time by leveraging its know-how in engine manufacturing – including low-pressure moulding and die-casting. Tapping into this knowledge has allowed Toyota’s engineers to develop an optimally shaped mould that enables replacements in just 20 minutes.
In addition, the use of proprietary analysis technology improves the quality of castings, thereby reducing the number of defective moulds. By employing this unique architecture alongside its approach to casting moulds, Toyota is targeting a 20% improvement in productivity compared to current industry standards.
Self-Propelling Production Line
The self-propelling line concept is already implemented on certain welding lines at the Toyota Motomachi Plant and forms the basis of future development and roll-out for new generation vehicle manufacturing. This new in-factory transport technology significantly improves the flexibility of line layouts and eliminates the need for conveyors, thereby drastically reducing plant investment and production preparation lead time.
Self-propelling part-assembled vehicles operate safely at a speed appropriate to mass production due to several factors: their sensors are capable of recognising vehicle, people & objects, and all processes from equipment to development & mass production are insourced using the knowledge and experience that Toyota has accumulated through autonomous driving technology development.
Further Steps Towards The Mass Production Of Next-Generation Batteries
Toyota is aiming to commercialise its next-generation Popularisation liquid-electrolyte battery in 2026-27. The new battery is designed to deliver high quality at a lower cost by using lithium iron phosphate (LiFePO) as its core material. In order to maximise the Popularisation battery’s performance and minimise its cost, it is essential that during the coating process the paste must be applied to the metal foil evenly and in large quantities – at speed. Toyota is able to achieve this by leveraging its 26 years of coating knowledge coming from its production of fuel cell stacks, and of batteries for hybrid-electric vehicles. Toyota’s first solid-state battery is expected to be ready for commercial use in 2027-28.
The solid-state battery has ions moving through a solid. Therefore the anode, cathode, and solid electrolytic layer should be tightly bonded to each other without gaps. Toyota has established the process for stacking batteries at high speed and high precision without damage to the different materials using an innovative mechanism and synchronous control technology.