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| Eighteen “monozukuri-focused” assembly line design and visual factory management principles with DENSO industrial examples | |||||||||||||
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| The Authors | |||||||||||||
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| Paul G. Ranky, Department of Industrial and Manufacturing Engineering and IT Departments, New Jersey Institute of Technology (NJIT/MERC), Multi-lifecycle Engineering Research Center, Newark, New Jersey, USA | |||||||||||||
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| Abstract | |||||||||||||
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| Purpose – To offer lean design and assembly principles with a focus on “monozukuri,” meaning sustainable, environmentally friendly factories and products with simultaneously integrated product and process designs. Design/methodology/approach – Based on extensive study of products, processes and factories, 18 “monozukuri-focused” product, process, factory design and management principles are explained by the author. Findings – The rule-based approach to designing lean, sustainable, “monozukuri-focused” flexible products, processes, production systems and factories will reduce waste at all levels, and create new opportunities for satisfying dynamically changing market needs. Originality/value – Reveals 18 lean design and assembly line design and management principles with some practical industrial examples. | |||||||||||||
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| Article Type: Case study | |||||||||||||
| Keyword(s): Lean production; Assembly; Sustainable design. | |||||||||||||
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| Assembly Automation | |||||||||||||
| Volume 27 Number 1 2007 pp. 12-16 | |||||||||||||
| Copyright © Emerald Group Publishing Limited ISSN 0144-5154 | |||||||||||||
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| Introduction Based on the author's factory visits at DENSO's Takatana plant in Japan, and in Michigan, USA, we discuss 18 “monozukuri-focused” lean assembly line design and factory management principles, discussed in this paper. DENSO was chosen for this study, due to the fact that they are the leading global supplier of advanced automotive technology, systems and components, and because of their eco-friendly, sustainable design and manufacturing/assembly solutions, often referred to as the “monozukuri-focus.” DENSO's fundamental mission is to make things that last by perfecting the art of integrated eco-friendly, sustainable design for assembly, or in Japanese, a dedication to “monozukuri” (Ranky, 1983). This fits into their product design for assembly, assembly line design and factory management principles. They are keen to achieve:
In this paper we introduce and illustrate some of the 18 “monozukurifocused” lean design and assembly principles, based on visits to DENSO's Takatana, Japan, and the Battle Creek, Michigan, USA plants, with practical instrument cluster, and other body component assembly examples (Montgomeri, 2006; Ranky, 2006a, b, c). Principle-1. Design and simulate in the digital domain, meaning on the screen first, before anything is built on the factory floor, following ecofriendly, monozukuri-focused product, assembly system and factory design rules “Monozukuri” means eco-friendly, sustainable design, manufacturing and assembly for the purpose of reducing waste, helping the environment, the communities and in the long-term increasing profits and product quality. The other key concept to notice here is the extensive use of advanced digital manufacturing/assembly/packaging and flexible manufacturing/assembly system design and simulation tools. Principle-2. Design products for automated assembly, but start with mostly human operated assembly systems and gradually introduce the appropriate level of automation “Monozukuri” here means stay as lean, agile, reconfigurable and flexible as you can by employing your best associates along the semi-automated assembly lines, because they will help you to iron out issues at an early stage. Furthermore, by being able to assemble several different types of product on the same line, your kanban system will not suffer due to major order fluctuations. This principle should not be misinterpreted though, by saying, that “The Japanese don't invest in automation anymore … ” The contrary is the truth. In Japanese owned and operated companies in Japan and elsewhere in the world, engineers, management and associates work closer together than typical traditional Western management controlled companies. This is because they are motivated to gradually learn together the areas where automation offers clear benefits. As examples consider the partial automation aspects of a semi-automated assembly and test line in the Takatana factory in Japan (Figure 1) and the automated, robotized inspection station with built-in advanced vision in DENSO's Michigan factory (Figure 2). Since, high quality inspection is always key, QC is performed 100 percent on every product to assure zero defect production. QC robots continuously working in three shifts with advanced vision systems typically perform better than human operators; this fact is accepted by all involved. The interesting fact is, that if the robot finds a quality issue on a part, a human operator will support the re-test and optional re-work process, based on accurate computer displays, pointing exactly to the areas where the robotized inspection system found the issue. As time goes by and experience grows on the line, the human operators help the robotized system developers to improve on sensors, software and integration, resulting in smarter and better systems on the lines. Principle-3. Management decisions should reflect long-term thinking, even if this means initially hard-to-accept financial returns “Monozukuri” here means developing a culture for eco-friendly, lean, agile, reconfigurable and flexible production with a long-term view. It reflects a philosophy that supersedes short-term decision-making. It means work hard, grow with your customers, and align the entire organization that is greater than just making profit. It also means continuous urge to generate value for customers, and the society in a responsible manner. Principle-4. Develop outstanding leaders who fully understand and support the company philosophy, and wisdom This means identifying and growing leaders from within the organization who truly understand and share the wisdom, as well as are seen as role models for others to follow. Principle-5. Create a strong company culture that does not tolerate poor quality work and focuses on continuous improvement and waste reduction methods and tools “Monozukuri” here means continuous waste reduction, continuous improvement, and a strong and stable culture in which company values are respected and the benefits are widely shared. Principle-6. Good leaders will spend time at all levels of the company to thoroughly understand all aspects of a decision (genchi genbutsu) The best managers and leaders know their people, their systems, and their strengths and weaknesses, just as a captain of a ship; therefore continuously strive for improvement. The best practice here is to personally observe processes and data BEFORE any major decisions are made in respect of the associates, the product, the line, or the factory. Principle-7. Your company supply network plays a key part in designing products, processes and systems, therefore help them to continuously improve Suppliers are crucial, in particular when companies increasingly become global. Since, in many cases major product recalls have their roots in poor supplier products, it is essential to have respect and offer help to supply chain companies too. This of course, does not exclude continuously challenging business partners to grow, improve quality, and reduce cost. Supply-chain “marriages” can be long term, but do not have to be forever … Principle-8. Decisions should be achieved by means of team consensus “Monozukuri” here means that for every important decision several alternative decisions should be considered by an able team, and these decisions should include the environment too. (The Japanese call this decision process the “nemawashi”.) This means discussing problems and solutions with everybody involved, and every realistic option and outcome considered. The key here is to maintain a strong direction without sidetracking due to short-term gains. Principle-9. Design continuous process flow with built-in flexibility and agility to be able to produce several (e.g. 5-8, or even more) different product types on the same line “Monozukuri” here means stay as lean, agile, reconfigurable and flexible as you can, because order fluctuations can happen. The key here is good product and process design, that focuses on reusable, well-tested objects. Other key elements are flow production in which waiting time is not tolerated, and integrated workflow with visual factory controls (see also Principle-17), so that every associate on the line, as well as managers can immediately see waste, and act (Figure 3). Principle-10. Balancing the workload is essential to avoid high WIP (work-in-progress) and buffer size fluctuations (heijunka) The key is not to overload associates, but to achieve a well-balanced, steady flow of operations during which high quality can be maintained. Principle-11. The production control system should always focus on producing based on the market's needs, not the factory's maximum capacity The kanban, or “pull” production system should not be limited to individual lines inside the factory, but should also be well integrated into the supply chain of suppliers and customers. This literally means just-in-time production throughout the entire system with inventory holding times as short as 3-3.5 h! (Easier said than achieved …) The benefits are huge since all supply chain and customer chain factories work in balanced harmony, therefore waste and cost is down. The risks of course, include running out of parts and stopping the line … (In such very rare cases DENSO will immediately turn the effected line into a “learning factory” and start “kaisen” activities: see Principle-15) (Figure 4). Principle-12. Follow reusable, standardized processes Reusable objects and well tested, standardized processes pay off on the computer screen in the digital design domain, as well as in real production. Principle-13. It is OK to stop the line if the associate recognizes a quality issue that needs to be fixed immediately (jidoka) This principle underlines the important fact, that if any of the associates detect an error that can or will effect product quality, can and should stop the line without penalty. Obviously the goal is to prevent such cases by means quality product and process design, well-educated associates, statistical quality control and variation trend analysis, by means of visual factory controls, and by building quality culture into the product, the people, the systems, and even the users. “Jidoka” literally means machines with human intelligence. “Smart” machines, such as automated robotized inspection stations with vision (as shown in Figure 2) are typical implementation examples for “jidoka.” Principle-14. Technology used should be the appropriate, tested level of technology versus the latest, for the sake of using the latest technology The latest technology does not always represents the best, nevertheless should be explored. Technology should support associates on the lines, not replace them. In Japanese factories processes are ironed out by the most experienced operators first and automation is brought in only after that. Principle-15. Design continuous improvement techniques, or Kaisen methods into every process There is no doubt that our Japanese colleagues are the masters of gradual improvement and we should collectively learn from each other. As they define it in Japan: Improvement is an attempt to breakthrough from the present and control is an effort to prevent slip-off from an improved stage. These two complement each other as two wheels of the same cart to create a better workshop. Principle-16. Design products and processes in the digital domain first, to avoid MUDA, MURA, and MURI MUDA means waste. It means many different types of waste, including: unbalanced workload, long waiting times and uncoordinated action plans between departments, as well as waste in terms of, “is the right man doing the right job?” MURA means irregularity, or differences and variability caused by men. MURI means stress and strain. It reflects on problem areas such as: is there a shortage of manpower? Is there an opportunity to simplify the operation unloading strain of the operators? Principle-17. Visual factory Visual factory often means simple, nevertheless effective visual information aids, including signs, charts, pictures illustrating processes, color coding, machines and workstations with red, yellow and green lights, scoreboards, and others. At an advanced level, visual factories deploy real-time interactive multimedia support systems, advanced statistical control methods and networks to make everybody aware of how the factory works at the time. It is truly amazing how even simple visual factory controls can improve a line or factory (see again Principle-10, “heijunka”). The key here is the culture of willingly and openly sharing versus hiding … Principle-18. Strive towards the wisdom of a learning organization through analysis and reflection (hansei) and continuous improvement (kansei) The key “monozukuri” drivers and achievable gains with the introduction and execution of this principle include performance advantage through improved organizational capabilities, and alignment of improvement activities at all levels to an organization's strategic intent:
Summary The discussed 18 “monozukuri-focused” assembly line design and visual factory management principles offer major long-term benefits to all involved. This win-win formula is clearly visible in the studied Japanese and American DENSO factories, as well as in other factories like Toyota, Honda, Nissan, Apple Computers, Dell, HP, Fanuc Robotics, GE Fanuc, Mori-Seiki, BMW, and many others. The core message of these principles is to design eco-friendly, quality products that customers need, want and desire, produce exactly as much as needed, just-in-time, to reduce inventory waste and cost throughout the entire global supply-chain. This is very difficult to achieve in practice. It is a proven fact, that by deploying these generic principles to literally any factory or system, customer satisfaction will increase through quality products and services, and global growth will become reality through anticipation of change. This is because accepting the fact, that continuous improvement is a natural change process, environmental preservation will become a natural integral part of everything we do in harmony with society, including individuals. The reality is that despite the fact, that these principles sound truly very simple, there is a lot of science, engineering and management hiding behind them. This is often misunderstood and even ignored by management, as well as the academic research community. Implementation is the hard bit here, because it needs collective acceptance and harmony throughout the entire factory, and even in the global supply chain. Analysis performed in General Motors, Delphi, DaimlerChrysler, Ford, and many other companies have clearly shown, that they are all trying to work hard towards implementing these principles, nevertheless what they are missing is the “collective acceptance,” or in other words the “quality culture” at all levels. Several programs, such as TQM, Six-sigma, Lean, Business Process Improvements, Visual Factory, and others tried to fix this, nevertheless most of them have only isolated impact unless the entire organization is prepared to change for the better. This is why Visual Factory management is a good place to start this culture change because the “rocks will become visible to everyone,” and that might trigger change. After this one should perform integrated process, requirements, and risk analysis, embedded into a statistical framework at all levels. This will bring truly major positive results, but this path is not a “quick-fix;” it is very hard work for those who truly believe in a sustainable, long-term, continuous improvement process.
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Friday, September 21, 2007
Eighteen “monozukuri-focused” assembly line design and visual factory management principles with DENSO industrial examples
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