Are Radical Improvements Too Risky? | John Dyer | IndustryWeek



” […] I can remember the day I shut down a major GE manufacturing plant like it was yesterday. The year was 1988 and I was working as a process engineer on the shop floor of building 5 in Appliance Park where we made refrigerators. […]”


Michel Baudin‘s comments:

The two stories in this article — about refrigerator assembly and a heating process — have the ring of truth. I have had similar experiences, both positive and negative

Both stories are morality tales and I don’t want to spoil them for you, so I won’t go into specifics. Read past the business-speak of “paradigms” and “significant changes, ” go straight to the stories, and draw your own conclusions as to their lessons on management.

Dyer’s own conclusions that follow, and his recommendations of tools like FMEA or DMAIC, are too specific for my taste. I understand he is explaining his approach, but it is beyond what is directly supported by the stories.

See on Scoop.itlean manufacturing

Is Lean A Science Based Profession or Tool Based Craft | Steve Spear | LinkedIn Pulse

“Is lean a bona fide management science based profession or a tool based craft? I’ll suggest that current practice and teaching is more the latter than the former and because of that, the influence of lean is far inferior to its potential.”


Michel Baudin‘s comments:

Within Manufacturing, management, engineering, and even consulting are professions. “Lean” per se is not a profession, but a loosely defined body of knowledge that all manufacturing professionals should possess to some extent.

Like Spear, we all tend to think of mechanical engineering as an application of Newtonian mechanics. In reality, however, it is not as if the field had developed from scratch based on Newton’s theories.

People had been making mechanical devices long before, and mechanical engineering as we know it actually came from the grafting of Newtonian mechanics onto an existing body of craft-based, empirical know-how.

As Takahiro Fujimoto pointed out, the Toyota Production System (TPS) was never designed from first principles but instead emerged from the point solutions and countermeasures Toyota employees came up with to overcome a succession of crises in the development of the company. What is remarkable is that they did coalesce into a system.

Lean is supposed to be a generalization of TPS to contexts other than car manufacturing at Toyota. The challenge of developing Lean is to reverse engineer principles from tools.

Over the past 35 years, many Japanese publications have described TPS, with authors like Taiichi Ohno, Shigeo Shingo, Yasuhiro Monden, Kenichi Sekine, Takahiro Fujimoto or Mikiharu Aoki…

These publications have made many of the tools of TPS accessible to anyone willing to study them. They have been less effective, however, at showing how the tools work together as a system, and even less at spelling out underlying principles. It is something I have attempted in my books.

Little of the content of TPS has made its way into Lean, as promoted and practiced in the US and Europe, where it boils down to drawing Value-Stream Maps and running Kaizen events that have little to do with TPS.

TPS still needs to be studied, and its essence abstracted into a theory that is neither false nor trivial and provides principles that can be practically deployed as needed in new industries. I agree with Spear that there is great value in such a theory, but it has to exist before we can use it.

See on Scoop.itlean manufacturing

Lean and Management Processes

An online sparring partner of 15 years, Bill Waddell, concluded our latest exchange with the following:

“Lean is comprised of three elements: Culture, management processes and tools. While you obviously have a keen awareness of the culture and tools, you continually under-appreciate the management processes, Michael.”

It is a 3-step progression: first, Bill makes a general statement of what Lean is, then he points out a serious shortcoming in my thinking, and finally he misspells my name.

As I am not trying to go global cosmic with Lean but instead remain focused on Manufacturing, rather than Bill’s three elements, I see Lean as having the four dimensions identified by Crispin Vincenti-Brown. Whatever you do has some content in each of the following:

  • Engineering, in the design, implementation, and troubleshooting of production lines.
  • Logistics and Production Control, covering both physical distribution and the processing of all information related to types and quantities of materials and good.
  • Organization and People, covering the structure, sizing, responsibilities and modes of interaction of departments in production and support, to run daily operations, respond to emergencies, and improve.
  • Metrics and Accountability. How results are measured and how these measurements are used.

Attention must be appropriately balanced in all of these dimensions and, if one is under-appreciated in the US, it is Engineering, not Management. Metrics and organization issues hog the attention; what little is left over goes towards Logistics and Production Control, and Engineering is taken for granted. The tail is wagging the dog, and reality bites back in the form of implementation failures.

What is a management process, and how does it differ from a tool? The term sounds like standard management speak, but, if you google it, the only unqualified reference to it that comes up is in Wikipedia, where it is defined as “a process of planning and controlling the organizing and leading execution of any type of activity.”

Since Henri Fayol, however, we have all been taught that the job of all managers is to plan, organize, control, and lead. In those terms, there doesn’t seem to be any difference between a “management process” and just “management.” All other Google responses are for the processes of managing different functions, like the “Project Management Process,” “Performance Management Process,” “Change Management Process,” or the “A3 Management Process.” The corresponding images are a variety of box-and-arrow diagrams, pyramids, wheel charts, dish charts, and waterfalls/swim lanes, as in the following examples:

A manufacturing process is the network of tasks to make a product from materials — with routes that merge, branch, and sometimes even loop. A business process, likewise, is a network of tasks to turn inputs into outputs, like the order fulfillment process that turns customer orders into deliveries. A political process  is also a network of tasks leading to a particular result, like the election of a president or the approval of a budget. So, what about a management process? And what is the level of appreciation that it deserves?

Bill is the one who should really explain it, but, if I were to use this term, at the most basic level it would be for what I have been calling protocols, by which I mean the part of management work that is done by applying sets of rules or procedures rather than making judgement calls. They are pre-planned responses to events that might occur but are not part of routine operations. It can be the arrival of a new member into a team, the failure of a truck to show up, or a quality emergency.

This is the spirit of Toyota’s Change Point Management (CPM), in which the pre-planned responses are prepared by the teams that are potentially affected by the events and posted in the team’s work place. When the event occurs. all you have to do is retrieve the plan and you know what to do. And it is usually a better plan than what you would have improvised in the heat of the moment.

At a higher level, I would call process a protocol used to organize the way you make judgement calls. You can’t set the strategy of a company by applying rules, but you can use Hoshin Planning to organize the way you do it. A process like Hoshin Planning is akin to the rules of a game; it doesn’t determine how well the managers play. If they just comply with a mandate and go through the motions, they will produce a certain result. If, on the other hand, they understand what they are doing, connect it to their own work, and see the value in  it, then they will produce a different result.

A good process does not guarantee a good outcome, and great teams have been able to coax performance out of dysfunctional processes. What is the proper level of appreciation for these management processes? Clearly, there is more to management than processes, and the best managers are those who excel at endeavors for which there is no script.

I learned to appreciate the relationship between management and engineering in Manufacturing from working with my mentor, Kei Abe. When he took me on as a junior partner in 1987, one of the first things I learned from him was to approach problems in a holistic manner, simultaneously at the technical and and the managerial levels. I saw him coach a shop floor team on the details of SMED in the morning, and the board of directors on company strategy in the afternoon. It’s not a common mix of skills, but I believe it is what a manufacturing consultant should have.

Using videos to improve operations | Part 2 – Management Preparation

Whether on the shop floor or elsewhere, starring in a video makes people nervous, particularly when they don’t know how it will be used and when it is done by strangers. On the shop floor, particularly when unions are present, operators fear that the videos recordings will simply be used against them and to  justify layoffs. Unless these fears are put to rest before the shoot, it will be tense and, if it happens at all, the quality of the data will be affected.

Following are key steps to follow:

    1. Have a clear objective. Videos can be used for many purposes:
      • Setup time reduction. This is the most common current use in Lean implementation.
      • Work Sampling. A time-lapse video of a work area can be used as a series of snapshots on which to count the people and machines by category of activity, providing rough estimates of proportions of time spent walking, waiting, carrying parts, processing work pieces, etc.
      • Analysis of team coordination. You record from a distance the movements and state changes of multiple people and machines. You don’t see the details of what each one does, but you identify situations where they:
        • Walk long distances, empty-handed or carrying heavy parts,
        • Cause others to wait,
        • Deadlock each other,
        • Fix the work done by others,
      • Details of work done at an individual station. You focus on the hands of one operator through a sequence of steps at a work station, with the goal improving both individual steps and their sequencing.

      This is necessary not only to plan the shoot so that the video supports the objective, but also to identify the people who will be recorded and the ways in which the analysis may affect them.

    2. Secure the consent of the participants. The people recorded in the video are not the object of a project but participants in it. It should only be done if they and their management agree. This entails the following:
      • Review the project with the direct supervisor of the area first, and proceed only if he or she supports it. The supervisor needs to agree to let operators participate in video analysis sessions, during work hours if they can be temporarily replaced in production, and in overtime otherwise.
      • If the plant is unionized, review the project with the union leadership. Unless prevented from doing so be constraints external to the plant, unions support the project once they are reassured that:
        • The purpose is not to make people work harder.
        • It is no threat to job security.
        • It usually improves safety.
      • Review the project with the operators, in the presence of their supervisor and a union representative if applicable.
      • There must be a clear policy on the handling and dissemination of videos after the analysis. The principle to follow is that what happens on the shop floor stays on the shop floor. The videos are not to be shared with any outsider to the project. VHS cassettes were easy to safeguard; MPEG files on hard disks are a different challenge. They need to be organized in a video database with proper indexing and safeguards, which is a whole other subject.

Using videos to improve operations | Part 1 – Overview and Motivation

This is the first in a series of posts about  the use of video technology to improve operations. This technology is now so pervasive that it is nearly impossible to buy a phone that does not include a camera capable or recording footage that is good enough for broadcast news. Journalists use amateur videos to show storm damage or expose human brutality. We use it to identify improvement opportunities in operations.

For long-time followers of this blog, this is closely based on comments I posted 18 months ago about a news article on the application of a sports video analysis package to manufacturing. The forthcoming installments, on the other hand, are completely new. 


Frank and Lillian Gilbreth did it 100 years ago

Motion pictures have a long history in manufacturing. In 1895, the first film ever publicly projected onto a screen showed women leaving the Lumière Brothers factory in Lyon. In 1904, the American Mutoscope and Biograph Company shot several scenes in Westinghouse factories. In 1913, Frank and Lillian Gilbreth were probably the first to use this new technology to analyze operations, and a compilation of their films is available on line, which shows that, from the very beginning, the camera was much more than a substitute for the stopwatches used by Taylor. As is obvious from watching the Gilbreth films, where Taylor measured in order to control, the Gilbreths observed in order to improve. Taylor’s greater fame or notoriety, however, obscured this fundamental difference in the public mind, and made workers as wary of cameras as of stopwatches.

According to psychologist Arlie Belliveau:

The Gilbreths used workers’ interest in film to their advantage, and encouraged employees to participate in the production and study of work through film. Participants could learn to use the equipment, star in a film, and evaluate any resulting changes to work practices by viewing the projected films in the labs or at foremen’s meetings. Time measurements were made public, and decisions regarding best methods were negotiated. By engaging the workers as participants, the Gilbreths overcame some of the doubt that followed Taylor’s time studies.”

In other words, these pioneers already understood that, unlike the stopwatch, this technology enabled the operators to participate in the analysis and improvement of their own operations.

Until recently, however, the process of recording motion was too cumbersome and expensive, and required too much skill, to be massively practiced either in manufacturing or in other types of business operations. In addition, most managements failed to use it in as enlightened a way as the Gilbreths, and manufacturing workers had a frequently well-founded fear that recordings would be used against them. As a consequence, they were less than enthusiastic in their support of such efforts.

Use in Setup Time Reduction

Setup time reduction is probably the first type of project in which it was systematically used, first because the high stakes justified the cost, even in the 1950s and second because its objective was clearly to make drastic changes in activities that were not production and not to nibble a few seconds out of a repetitive task by pressuring a worker to move faster.

The Vanishing Cost of Shooting Videos

Technically, the cost of shooting videos has not been an issue since the advent of the VCR in the 1980s. Analyzing a video by moving forward and backwards on a cassette tape, while it appears cumbersome today, was far easier than dealing with film. The collection of data on electronic spreadsheets also eliminated the need to use counterintuitive time units like “decimal minutes.” Adding columns of times in hours, minutes and seconds was impractical manually but not a problem for the electronic spreadsheet.

With videos now recorded on and played back from flash memory, and free media-players as software, not only is moving back and forth in a video recording is easier, but the software maps video frames to the time elapsed since the beginning. We could manually transfer timestamps read from the bottom of the video player software window into electronic spreadsheets and have the spreadsheet software automatically calculate task times as the differences between consecutive timestamps.

Analyzing Data in Video Form

While this approach has been a common practice for the past 15 years, video annotation software is available today, which helps break down the video into segments for steps, label them, categorize them, and analyze them.

You can also use it to structure the data and generate a variety of analytics to drive improvements or document the improved process through, for example, work instructions. Over the previous approach, video annotation has the following advantages:It automates the collection of timestamps. Reading times on the video screen and typing hem into an Excel spreadsheet is tedious and error-prone. Plowing through the details of a 30-minute is tedious enough already.

  1. Within the annotation software, each video segment remains attached to the text, numeric or categorical data you attach to it. One click on the data brings up the matching video segment.
  2. Using parallel tracks, you can simultaneously record what several people and machines do. Of course, you can do that without annotation software too, but it is more difficult.
  3. You can still export the data you collect and analyze it in Excel, but you can also take advantage of the software’s built-in analytics.

“Video time studies” is too restrictive a name for what we do with videos. It implies that they are just a replacement for a stopwatch in setting time standards. But what we really do with videos is analyze processes for the purpose of improving them, and this involves more than just capturing times. The primary pupose of the measurements is to quantify the improvement potential to justify changes, and to validate that they have actually occurred.

Remaining Challenges

Putting this technology to use is not without challenges. Video files are larger than just about any other type we may use, be they rich text, databases, or photographs. And they come in a variety of formats and compression methods that make the old VHS versus Betamax dilemma of the VCR age look simple. More standardization would help, and will eventually come but, in the meantime, we have to learn more than we want to know about these issues. Functionally, the next technical challenge is the organization of libraries or databases for storage and retrieval of data captured in the form of videos. The human issues of video recording and analysis of business operations, on the other hand, remain as thorny as ever.

Lean implementers: don’t forget engineering!

Just about everybody says that the involvement and personal engagement of top management is the main challenge in Lean implementation. “Key to the success of lean manufacturing,” said the keynote speaker at an industry association meeting in Santa Clara, CA, “is that the leadership team needs to fully buy into the method and remove workplace obstacles so that employees can achieve results.” While he didn’t say it, I am sure his audience heard that management doing as he says is all it takes to implement Lean successfully.

In an informal survey taken recently by blogger Vivek Naik among his readers, no one mentioned insufficient mastery of the engineering and management tools of Lean as a cause of failure. The existence of tools is generally recognized, but most consultants and implementers take them for granted. They are assumed to be simple, widely known and not new. Some, like Bill Kluck, even call the tools “trick shots.”

When you read that the details of Lean tools are widely known, you wonder where and by whom. How many manufacturing managers or engineers do you know who understand heijunka, cell design, work-combination charts, SMED,  the proper use of andons, mistake-proofing, or jidoka? Considering that these tools are the results of 75 years of development at Toyota, and that most of the Japanese literature on Lean is about technical content, I find this dismissal cavalier, to say the least.

It does not happen in other human endeavors, like building a world class soccer team.  Top management commitment is obviously required, but no one would claim that it is sufficient. You don’t hear of dribbling, passing, shooting, receiving or throw-ins as low-level skills that everybody has anyway and that you don’t need to focus on. Soccer teams actually train relentlessly to develop and maintain these skills, and everybody involved, even the fans, fully realize their importance and admire the star players for their mastery.

To understand the issues, and remedy this situation, I would like to dive deeper into the following topics:

The engineering dimension of Lean, and the other dimensions

So why is it different in the competitive game of manufacturing? For one, it is more complex than soccer, and few people have a holistic view of it. One who does is my colleague Crispin Vincenti-Brown, and he has identified four dimensions to this game, and you must pay attention to all if you want to win. They are as follows:

  1. The engineering of production lines.
  2. Logistics and production control.
  3. Organization and people.
  4. Metrics and accountability.

4 dimensions of manufacturing

In the US, the Lean movement has ignored the engineering dimension. Logistics receives some attention, but Lean programs are overwhelmingly focused on the last two: organization and people issues, and metrics. It is out of balance, and I believe this is a key reason for Lean programs to fail.

Lean implementers, whether employees or consultants, come from a variety of backgrounds. In the US, few are engineers. You see MBAs, psychologists, marketing people, and the occasional cognitive sociologist and defrocked priest. There is nothing wrong with having all these different perspectives, as long as they don’t blind you to the whole picture. The psychologist takes engineering for granted while the engineer does the same for people issues and the production control manager thinks that everything revolves around planning and scheduling….

On the one hand, you cannot have a successful implementation unless you address all these dimensions in the right sequence. On the other hand, you cannot expect any individual to master all of them, but you need a team that does, in which every member understands that his or her perspective is not the whole picture, and leadership that can pull all the strings into a coherent approach.

What is special about engineering on a factory floor?

This still does not explain why it is Engineering of production lines that is given short shrift, even in a country like the US, that has contributed so much to this field, and that still has a vibrant engineering community in other technical specialties. What is it about the engineering of production that sets it apart?

The heat of the forge, the sparks from welding, or the din of the assembly line, and interactions with the people who work in these environments,… are not for everybody. Most universities do not know how to teach this kind of engineering. Its subject matter straddles what they call Industrial Engineering and Manufacturing Engineering.

Industrial Engineering (IE), as taught in American universities, is generically about how people work, and gives you no process-specific knowledge. Manufacturing Engineering (ME), on the other hand, is heavily focused on metal working operations, as if these were the only processes worthy of the name “manufacturing.” In principle, you should be able to become a Manufacturing Engineer specialized in all sorts of other fabrication or assembly processes, but the label is in fact used only in metal working.

We could expect, however, those who pursue degrees in IE or ME  to be comfortable on a production shop floor, but most aren’t. Some years ago, my colleague Hormoz Mogarei and I gave a seminar to PhD candidates in Industrial Engineering at Stanford University. We wanted to tell them what we did to get them interested in working with us. Their response, however, was that it was beneath them, and that they had not gone this far in school to do such low-level work.

For factory work, Shigeo Shingo had identified two types of engineers to avoid: the catalog engineer, whose solution to every problem is buying new equipment, and the “no” engineer, who always has a reason why it can’t be done, has been tried before, or won’t work. One more category that did not exist in Shingo’s day but does today is the PowerPoint engineer, whose focus is animating slides.

Historically, with the exception of Lillian Gilbreth who had a PhD, the key innovators in this field, from Frederick Taylor, Frank Gilbreth and Alexei Gastev to Taiichi Ohno and Shigeo Shingo were all self-taught and had no advanced degrees. To this day, the engineers who are most comfortable and effective on a production shop floor started working there as operators in their youth and later went back to school or  learned  through continuing education or apprenticeship programs that alternate extended internships with classroom training. These engineers combine the requisite technical knowledge with an understanding of the operator experience and the ability to work with operators on improvements.

Engineers in Lean implementation

And having practical, shop-floor minded engineers in your plant is still not sufficient. You also need to use them effectively. In manufacturing, if you provide an “engineering sandbox,” organize for people to tinker in it, and provide some form of recognition, you will get results. The engineering sandbox is a space set aside and outfitted with the resources needed for tinkering, experimentation, and prototyping. It is used both by individuals and teams.

Engineering Sandbox

Engineering Sandbox

In Wikipedia, the space you can use to draft an article or an edit before publishing it is called your “sandbox,” and it is similar in concept to the engineering sandboxes you find in factories, that are often called “Kaizen areas” even though the experimentation that takes place can exceed the scope of what is commonly designated as Kaizen. This space is best located in a secluded area, away from heavy traffic and prying eyes and, as it is shared by multiple individuals and teams, access to it must be managed accordingly and often takes place outside of regular working hours. Chihiro Nakao calls this activity “moonshine.”

The implementation of Lean involves engineering projects at multiple scales, from continuous improvement to new plant design. Which no engineering group can be large enough to execute on its own. While many companies set up a “Lean Engineering” group and task it with transforming the entire plant, it cannot work. The engineering group does not have the bandwidth to do no matter how hard its members apply themselves and, even if they did, the production organization would not own their output and would reject it.

Lean engineering group forging ahead

Lean engineering group forging ahead

The only way it can practically be done is by the production organization, under the leadership of its management at the appropriate level, with the engineers in a supporting role. The concepts emanate from the production organization. The engineers help with calculations, research available resources, generate technical drawings, and coordinate the use of contractors if needed. And they apply the lessons learned through improvement to new plant and new line designs where they play a central role.

NIX Octopus

Retrofit to a multicavity injection molding machine

At the start of setup time reduction projects, the focus is on organizing to prepare better before stopping the machine, which achieves initial results, mostly through the work of production operators. But to reduce setup times from 1 hour to less than 10 minutes, you need to go further and modify the machine, which requires engineering. And it’s not all about hardware. More and more machines are computer-controlled, and also require changes to their process programs. The picture to the left shows a device conceived and built by plant engineers, and retrofitted to an injection molding machine to separate the parts by cavity and better trace quality problems.

Correcting the imbalance in the US Lean movement

I am not the only one who has been working to lack of attention to engineering in the US Lean movement. J.T. Black, a professor of IE at Auburn University in Alabama, now in his seventies, was possibly the first American academic to recognize the significance of Lean and make it central to his teachings. Art Smalley, a consultant who is a Toyota alumnus, has also been vocal. But it is an uphill battle. Two of my books, Lean Assembly and Working with Machines, are on this subject, and both are outsold by Lean Logistics, which isn’t.

The baton-touch approach

The following question came this morning from Diogo Cardoso:

What is baton-touch in terms of product oriented manufacturing systems? I have made a deep research about this on Science Direct and other resources but I can find nothing more than an inconclusive paragraph.

Your researched the wrong sources. You could have found your answer in Working with Machines, pp. 140-142. Baton-touch is one of three approaches used to design operator jobs in cells, the other two being the caravan/rabbit-chase and bucket-brigades. The key differences are as follows:

  • In the baton-touch method, each operator performs a fixed subset of the cell’s operations, organized in a fixed sequence. It is commonly used in cells requiring three or more operators making a narrow range of products with similar work content.
    The baton-touch

    The baton-touch

  • In the caravan or rabbit-chase method, the operators follow each other through the entire sequence of operations in the cell. It requires each operator to be skilled in all the operations of the cell, and works well with up to two operators but breaks down with three or more operators, as they queue behind the slowest member of the team.
    The caravan/rabbit chase

    The caravan/rabbit chase

  • In the bucket-brigade method, the operators are in sequence, but the scope of each operator’s tasks varies. When the last operator finishes a unit, he or she takes over the next unit from the preceding operator, who in turn takes over from his or her predecessor, and so on, until the first operator, who starts the next unit. Bucket-brigades are used with a broad mix of custom or configurable products, and work when the faster operators are always downstream from the slower ones. For details, see John Bartholdi’s article on bucket brigades.
    Bucket brigades

    Bucket brigades

Wanna Sabotage Your Lean Implementation Effort? Try This | Lonnie Wilson | IndustryWeek

See on Scoop.itlean manufacturing

Most facilities that fail in a lean implementation have failed to create stable process flow. And by stable I mean statistically stable — a process that is predictable. (Wanna Sabotage Your #Lean Implementation Effort?

Michel Baudin‘s insight:

The way I read Lonnie’s article, he is saying that neglect of the engineering dimension of Lean manufacturing is the primary cause of implementation failure. I agree. It is a long article, but worth reading.

See on

From Ybry charts to work-combination charts

Ybry chart used on French railroads in 2013

Ybry chart used on French railroads in 2013

This is a screen shot from yesterday’s evening news on the France 2 channel, part of a story about TGV high-speed trains used on regular tracks to bring vacationers to ski areas. The TGVs, of course run at regular speeds on these single line tracks and must stop at sidings to let regular trains through in the opposite direction. In an earlier post, I discussed the charts invented by Charles Ybry in 1846 for railroad scheduling, and this newscast shows that they are still used in railroads today. Besides railroad scheduling, they are also used in the management of multiple, concurrent projects, and  I believe they were the basis for Toyota’s work combination charts.

The x-axis is time; the y-axis, position along the line. On the chart, the downward lines represent trains going down the line; the upward lines, trains coming up the line. When and where the lines cross, trains cross, and there must be a siding available. The news story had the TGV pilot call in his position on a siding to a control center in Chambéry where the chart was displayed. On the high-speed TGV lines, the signalling is all electronic, and the system automatically knows where the trains are; when you run a TGV train at reduced speed on a regular line, however, it seems that the driver has to report what happens the old-fashioned way.

I learned about these charts in Edward Tufte’s Envisioning Information, where he describes them as a special case of a “narrative of space and time.” Among the examples he gave were a similar railroad scheduling application from Switzerland 80 years ago and the development of Wagner’s operas over almost 50 years in the 19th century:

Trains running up and down between Neuchatel and Chaux de Fonds in Switerland in 1932

Trains running up and down between Neuchatel and Chaux de Fonds in Switerland in 1932

Development timeline of Wagners operas from 1835 to 1892

Development timeline of Wagner’s operas from 1835 to 1892

Work combination charts are a tool to design and communicate about production jobs that require operators to perform a sequence of operations on multiple machines that operate automatically between visits. This is a Japanese example of such a chart:

A Japanese work-combination chart example

A Japanese work-combination chart example

The concept looks similar, doesn’t it? I found this chart particularly useful when you need to plan the activities of more than one operator, as in the following example:

Work combination chart for machining operations

Work combination chart for machining operations

In the Legend, “Manual In” refers to time spent by the operator on the machine with it stopped; “Manual Out,” time spent on the machine while it runs.

To this date, in the US, this powerful technique is far from enjoying the popularity it deserves. It is generally perceived as “too complicated” and I still don’t know of any software tools that fully support it. In designing jobs that involve interactions between human and machines, however, the consequence of not using it is leaving about 50% of the potential productivity improvement on the table. It may take a project team an extra day to do it, but the result is achieving a 40% productivity increase instead of 20%. Details are discussed in Chapter 7 of  Working with Machines.

New assembly methods at Toyota

Toyota’s latest plants in Ohira, in Japan’s Miyagi prefecture and in Tupelo, Mississippi, feature new approaches to assembly. According to press reports, the Miyagi plant is small, with 900 employees making 250 cars/day for export to the US, with a plan to double output and employment. It was designed to require a minimal investment and be easy to change. The plant started operations shortly before the Fukushima earthquake and, even though it is the Northern part of Japan that was most affected, it resisted well and was able to resume operations about six weeks later.

This is how Barry Render described it:

“The Miyagi factory is designed for advanced low-volume, hyperefficient production, with 1/2 the workers and 1/2 the square footage of Toyota’s 16 other plants. Inside, half-built Corollas and Yaris sit side-by-side, rather than bumper-to-bumper, shrinking the assembly line by 35% and requiring fewer steps by workers. Instead of car chassis dangling from overhead conveyor belts, they are perched on raised platforms. This is 50% cheaper, and also reduces cooling costs by 40% because of lower ceilings. Finally, the assembly line uses quiet friction rollers to move the cars along. The rollers use fewer moving parts than typical chain-pulled conveyor belts.”

Toyota is not providing details, but I have been able to glean some information about it from the press and Barry Render’s blog, on the following features:

This is followed by a few conclusions.

Side-by-side assembly

Side-by-side assembly at Toyota Miyagi

Side-by-side assembly at Toyota Miyagi

I have seen side-by-side assembly at the Volvo Bus factory in Turku, Finland. In the picture of the building below, bus bodies are assembled in the hall on the left, side-by-side under they are mounted on a chassis and move forward on their wheels, laid out front to back in the hall you see in the background.

Volvo Bus assembly building in Turku, Finland

Volvo Bus assembly building in Turku, Finland

Volvo bus main assembly flows

Volvo bus main assembly flows

The ratio of width to length  is more favorable to this arrangement for buses than for cars. A straight assembly line with a front-to-back arrangement throughout would require a long and narrow building and a snaking line would have problematic turnarounds. With cars, the side-by-side arrangement seems suitable for work done at the front or the back of the car, such as installing headlights or bumpers. but less for work that requires access from the middle, such as installing instrument panels or upholstery. The following press picture (AP), however, shows an assembly operation done inside the car body in what appears to be a side-by-side layout. It implies that space for the part cart must be provided between cars, which forces them apart.

Assembly operation at Miyagi

Assembly operation at Miyagi

None of the available pictures from the Miyagi plant shows the raku-raku seat that was a prominent feature of the early 1990s designs and made it easier for operators to work inside the car bodies. Not only is a raku-raku seat an added investment, but it is also easier to use in a front-to-back than in a side-by-side layout.

Raku-Raku seat

Raku-raku seat in a 1990s plant

Modular paint booths

I could not find pictures or sketches of the Miyagi painting system. Following is how CNN Money described it on 2/18/2011:

“…Toyota developed a modular paint spray line. The modules can be built somewhere else and are assembled at the plant in a much shorter time. Advantage: Cost savings. However, you don’t build a modular paint spray line factory somewhere unless you intend to build a lot of paint spray lines. Usually, cars get three coats of paint, usually water-based, and usually each coat is dried with heat. Not in Ohira. Here, the third coat is applied onto the still wet second coat and both are dried together. Advantage: Huge energy savings, faster paint time. Lower expenses…”

Friction roller conveyors

Toyota assembly line new concepts 2011 Miyagi plant Conveyance

Following is how CNN Money described the Miyagi conveyor systems on 2/18/2011:

“Where the car moves along the floor, factories usually have below ground pits that house the motors, chains and gears that keep the line moving. Not in Ohira. Here, the cars move on maybe a foot high conveyor system that is simply bolted into the concrete flooring. Advantage: Cheaper to build, cheaper to tear down and rebuild somewhere else. The line can be lengthened or shortened at will. The assembly line doesn’t ‘grow roots’ as they say in Toyota-speak.”

Note that the sketch shows car bodies without wheels. In this system, the bar supporting the cars forms

A photographs of final assembly at Ohira shows operations done further downstream, with the wheels on:

toyota--ohira-plant-in-japan-front-to-back assembly line 2011

Assembly operations after wheels are put on

In this picture, the floor the operators stand on is flush with the assembly line,  meaning that it is either a classical line with the drive mechanism in a pit under the floor, or the operators are in a raised platform spanning the length of this assembly line segment.

Elevated platform versus suspension conveyor

Toyota assembly line new concepts 2011 Miyagi plant Suspension

From suspension conveyor to elevated platform

The following photographs contrast the suspension conveyor approach as previously used at Toyota with the elevated platform at Tupelo, Mississippi:

From these pictures, it is clear that the elevated platform is a cheaper system to build, but I can see two issues with it:

  1. Flexibility in vehicle widths. The Yaris and the Corolla differ in width by less than half an inch, and therefore the same elevated platform can accommodate both. A Land Cruiser, on the other hand, is 11 inches wider, which makes you wonder whether it could share an elevated platform with the Yaris. The jaws of the suspension conveyor, on the other hand, look adjustable to a broad range of widths.
  2. Ergonomics. Working standing with your head cocked back and your arms overhead is just as ergonomically inadequate in both cases. By contrast, the VW plant in Dresden, Germany, uses suspended conveyors that can tilt the body, which is both ergonomically better and much more expensive:
VW Dresden suspended adjustable conveyor

VW Dresden suspended tilting conveyor


The journalists take on the Ohira plant is that it is intended to prove a design for low-volume, low-cost, high-labor content plants that can be deployed easily in emerging economies with small markets. The designs of the early 1990s instead used more automation to make the work easier for an aging work force, with tools like the raku-raku seat. This is a different direction, addressing different needs. But why build it in Northern Japan rather than, say, the Philippines? It shows Toyota’s commitment to domestic manufacturing in Japan, and it is easier to test and refine the concept locally than overseas.