It is a recurring expression in forums, conferences, and papers about Lean Leadership, but unclear because of the ambiguity about both leaders and standard work.
Philip Marris and I got to know each other on line, by participating in the same discussion groups, and met in person last year. The following conversation was recorded a month ago, in the Marris Consulting office in Paris:
Philip Marris: Hi, Michel, welcome to Paris! I am glad to take this opportunity to ask you about one of your books that I love, called Working with Machines. As far as I know it is one of the rare books on that subject, at least in terms of treating it in as much detail as you do, and it is about a subject very close to my heart, which is the relationship between the worker and the machine. Can you tell me what made you want to write the book and what the main messages are?
Michel Baudin: Well, what made me write it is that putting together systems of people and machines is central to manufacturing, and one of the things I learned from Kei Abe early in my career in consulting. There are a number of techniques like the work-combination chart, which is a typical tool of this area, and there is not very much written about it in English. You have books about automation, but the American books about automation say nothing about people. It’s like people are an afterthought. You get books about FMSs, and you see diagrams of machines, but you never see information about what people are supposed to be doing.
“[…] One of the things I find annoying, in this way, is that reducing variation and using standardization is said to mean everyone has to be the same and creativity is stamped out. This is not what Dr. Deming said at all. And the claim makes no sense when you look at how much emphasis he put on joy in work and the importance of using everyone’s creativity. Yet I hear it over and over, decade after decade.”
Sourced through Scoop.it from: blog.deming.org
Michel Baudin‘s comments:
Yes, the metric system did not stifle anybody’s creativity. By making commerce, engineering, and science easier, it actually helped creative people innovate, invent, and discover.
But when Deming says “Standardization does not mean that we all wear the same color and weave of cloth, eat standard sandwiches, or live in standard rooms with standard furnishings,” he seems to exclude the possibility that standardization could be abused.
A3s are still being touted as nothing short of a management revolution, but few organizations actually use them for operator work instructions, problem-solving, or hoshin planning. This raises the question of whether the objectives pursued with a paper format may not be easier to achieve with more recent technology. In this post, we consider options for operator work instructions. The other applications of A3s deserve separate treatment.
In the TPS Principles and Practice group on LinkedIn, I started a discussion by asking “What do we mean by ‘Standard Work’?” At that point, I saw it as whatever you do to ensure that same work is done the same way every time, regardless of time of day, production line, or factory; 96 comments later, my perspective has changed somewhat.
Ensuring consistency is, of course, essential but the tool to do it is Job Instruction (JI) rather than Standard Work. An operator’s complete job often involves multiple tasks, each of which has its own instructions. Standard Work builds on these instructions by specifying how these tasks are sequenced and combined to make effective use of people and equipment.
The main contributors were Len Canoot, Sid Joynson, Peter Winton, Casey Ng, David Hayden, MBA, Achyut Vaidya, Emmanuel JALLAS, Edward M. Wharton, Stephen Duquette, Erik Hager, Joachim Knuf, Paul Perry, Cid Li, Salvador D. Sanchez, Richard Kunst, Anders Penker, Andrew Williamson, and Steve Milner. The discussion also cited publications by Mike Rother, Art Smalley, John Shook, and Taiichi Ohno. If you want to see the whole discussion, please check it out on LinkedIn. This post is a synthesis , organized by topic and with illustrations added.
- Why ask about Standard Work?
- Standard Work and Process Stability
- Is Standard Work the Best Known Way?
- John Shook on Standard Work
- Standard Work versus Work Standards
- What is the Scope of Standard Work?
- Standard Work, Yokoten, and Revision Management
- Is Standard Work a Proper Focus for a Project?
- Is Every Problem a Deviation from a Standard?
- Is it “Standard Work” or “Standardized Work”?
- Standard Work for Leaders and Managers
- Standard Work and Project Management
- Standard Work versus Standards in general
- Standard Work and Changes in Takt Time
The House of Lean is a common metaphor. I use it sparingly, to make the point that the reason most Lean implementations in the US fail is that they are missing one of the two pillars:
For this purpose, I don’t need to break down the details of what is in the Foundation or what the Goals are. Others provide many more details about the House of Lean, using it as a map of the whole system, with a prominent place given to something called “Standard Work” or “Standardized Work”:
As we can see, there is with variation in Standard Work is supposed to mean. The Toyota description of Standard Work, for example, includes no reference to 5S or Visual Management, and explicitly excludes Job Instruction. The house on the right is from the Lean Enterprise Institute’s Lean Lexicon, and lists “Standard Work” and “Separating human work and machine work” as distinct entries but it is exactly what you accomplish with work combination charts, that are part of what Toyota calls Standard Work.
When you look it up on the Toyota Georgetown website or the LEI’s Lean Lexicon, it is about setting, for each operation, a takt time, work sequence, and required WIP, as expressed through a process capacity sheet, a work combination chart, and a work chart that is a layout diagram showing flows of parts and movements of operators between stations. (Click to see in full size.)
This is much more specific than what is meant by Standard Work is most discussions I have seen. I use capacity sheets, work combination charts and work station layout charts wherever you have to choreograph people working with machines, but I would not recommend them, for example, in manual assembly.
I have posted before about the work combination chart, as a powerful design tool for operator jobs, that also serves to communicate the sequence of tasks to operators, particularly new ones who are rotated into these positions. I see them as excellent tools, but it would not occur to me to label them “Standard Work,” because I don’t see any connection with the usual meaning of “standard.” I understand that “Standard Work” is an accurate translation of 標準作業 (Hyojun Sagyo), but I still don’t see a connection.
The following video clip, posted by JMA in Japan in 2009, shows what can be accomplished with work combination charts:
A process is stable if it can produce consistent output at a consistent pace. If it’s not stable, the first order of business is to stabilize it, but I don’t see standard work as the way to do it. You need to re-engineer the process to the point that its capability is no longer an issue and it is repeatable. Documentation and work instructions are an outcome of this effort, as needed to reduce the improved process to daily practice, but it is not the effort itself.
And the resulting documentation is not Standard Work. Standard Work, in the Toyota lexicon, is about takt time, work sequence, and required WIP, it doesn’t include process capability or even work instructions at the individual station level. It is only about the way you combine them in a line or a cell.
Most the Lean literature depicts Standard Work as an improvement backstop, a formalization of the improved process for the purpose of preventing backsliding. The following video is a quaint example of a PowerPoint animation used by a consultant to make that point. Note the yellow block preventing the wheel rolling back down:
Standard Work as “the best known way of doing the task” is the improvement backstop view, which I held without questioning it until I saw two articles disagreeing with it, and with each other, by Art Smalley .and Mike Rother. Mike Rother sees standard work as a target to shoot for rather than a backstop. Following is his rolling-wheel diagram:
Yet another version was included in John Hunter’s review of Gemba Walkabout, and it shows standard work used to block progress instead of helping.
These rolling-uphill diagrams remind me of the myth of Sisyphus, as described by Albert Camus. Sisyphus was a man condemned by the Gods to roll a boulder uphill everyday only to see it roll back down and start over, for eternity. See the following rendition by Marcell Jankovics:
Even if Sisyphus had had a backstop, it does not strike me as a particularly attractive metaphor for Kaizen.
Art Smalley sees Standard Work as a point of reference against which to measure future improvement. Taiichi Ohno does not say much about it in “Toyota Production System,” but in Workplace Management, he writes:
“There is something called ‘Standard Work,’ but standards should be changing constantly. lnstead, if you think of the standard as the best you can do, it’s all over. The standard is only a baseline for doing further kaizen. lt is kai-aku if things get worse than now, and it is kaizen if things get better than now. Standards are set arbitrarily by humans, so how can they not change?
When creating Standard Work, it will be difficult to establish a standard if you are trying to achieve “the best way.” This is a big mistake. Document exactly what you are doing now. lf you make it better than now, it is kaizen. lf not, and you establish the best possible way, the motivation for kaizen will be gone.
That is why one way of motivating people to do kaizen is to create a poor standard. But don’t make it too bad. Without some standard, you can’t say “We made it better” because there is nothing to compare it to, so you must create a standard for comparison. Take that standard, and if the work is not easy to perform, give many suggestions and do kaizen.”
John Shook published three e-Letters on the subject of Standard Work in October 2009, called “Five missing pieces in your standardized work.”
In Part 1, he describes the goal of having the same work done the same way everywhere as distinct from Standard Work. He calls it “commonization” as a translation of 横伝(Yokoten). Literally, Yokoten means “lateral transfer,” but it is meant about know-how, not people. You invented a better way to do a job, and you propagate it to everybody else who does the same job.
When he discusses the distinction between Standard Work and Work Standards, Shook includes under Work Standards not just the time a task is supposed to take but all its technical parameters, such as critical dimensions, tolerances, etc.
He describes Kaizen and Standard Work as two sides of the same coin. You can’t have Kaizen unless you have Standard Work as the basis for improvement, and a Kaizen project is not finished until its outcome is incorporated in Standard Work. But Standard Work as he describes it — with work combination charts — is used almost nowhere in American plants that claim to practice Kaizen. This means that some of the following must be true:
- The definition of Standard Work is too narrow. The need to specify takt times, work sequence and standard WIP is general, but different tools can be used to do it in different types of plants. A work combination chart, for example, is of limited value in a manual assembly process.
- Most plants that claim to practice Kaizen really don’t. In Japan, Kaizen designates small improvements to work methods, conceived and executed by the people who do the work, and US-style “Kaizen Events” are not Kaizen at all. A plant may run 50 Kaizen events per year and still not practice Kaizen. The means of implementing Kaizen include suggestion systems, that exist in many plants with varying success, and small-group, circle activities, that, in the US, are only found in Japanese transplants. As “Quality circles,” in the US, they were a fad in the 1980s; as Jon Miller pointed out in Quality Digest in 2011, circles are still going strong in Japan and in the rest of Asia.
- Some Kaizen activity is possible without Standard Work. What you really cannot do without is some metrics of before-and-after performance for the area that is improved, and these may be measured without Standard Work being in place.
The bulk of Part 2 is an example from Shook’s own experience on the Toyota assembly line in Takaoka in 1984. In Part 3, he describes Standard Work through the Purpose, Process and People framework, which he calls 3P. I had heard the “3P” acronym used before, by Shingijutsu people as the “Production Preparation Process,” which is something completely different.
5. Standard Work versus Work Standards
John Shook gives the following as examples of Work Standards:
- Assembly – apply xx pounds of torque
- Processing – heat treat at xxx degrees for x hours
- Healthcare – provide xx medication at xx dose
- Coffee – xx seconds for an espresso shot
- Journalism – a weekly column of xxx words
Last month, the Institute of Industrial Engineers (IIE) had a conference in Chicago on “Managing Work Standards.” It was exclusively about how long it takes to do work, not about what the work is. It is a sensitive topic because it is associated in the minds of production operators with Taylor’s “scientific management” and his determination to prevent operators from colluding to curtail output, which he called “soldiering.” For all his great contributions, respect for humanity was not Taylor’s strong suit. He probably would have said that this man should have borrowed money from his parents to start a business…
What we are doing when analyzing video recordings of operations is more in line with what Frank and Lillian Gilbreth did: observing processes in order to improve them. The difference in thinking is obvious from just viewing the films the Gilbreths made about bricklaying operations.
The Gilbreths were working to make the bricklayers’ job easier, not to make them exert more effort, but Taylor’s name is better known, and his legacy is a challenge to live down.
I think we need to improve the terminology. Having two different concepts called “Standard Work” and “Work Standards” is confusing, especially when Toyota uses “Work Standards” to mean something other than the IIE. Incidentally, it is confusing in Japanese too.
How about using “Work Instructions” for what Shook calls “Work Standards”?
What is the scope of Standard Work? I have seen described, I don’t remember where, as the process as seen through the eyes of a first-line manager — also currently known as production supervisor, group leader, or area coordinator, and formerly as foreman. This is a member of management, with direct responsibility for quality, cost, and delivery by a few teams of operators.
This person sees the work as a sequence of tasks to which operators are assigned and among which they rotate as needed. The technical and human unit processes at each station are the foundation on top of which the supervisor works. This would be why Standard Work is focused on takt time, work sequence and work combinations, as opposed to tolerances and job instruction (JI).
Also, Standard Work comes in the form of documents that are seen on the shop floor and that people are expected to follow. This makes them official, with revision numbers and approval stamps by stakeholders. Revision management on Standard Work is a whole other topic that I have not seen discussed anywhere.
Standard Work is a 2nd tier tool, like Visual Management, meaning that it is part of every project but never the focus of a project in its own right. In a brownfield situation, making “Standard Work” a project would lead you to attempt the precise documentation of work methods that need to be changed anyway, which would not be terribly useful and could bog you down for so long that you never get to do anything else.
On the other hand, if you identify specific dysfunctions in a process and organize a project to fix them, then you want the new and better way to be documented in such a way that it can be propagated across shifts and to other shops that do the same work.
Peter Winton feels strongly that it is. And this is about standards in general, not just Standard Work. If every problem is a deviation from standards, however, we have an easy way of solving all our problems: let us just scrap the standards… But it would not solve all our problems, would it?
It would solve some problems, because there are futile standards. As David Meier pointed out, when you set a standard, you create an opportunity for deviation, and the need to respond to these deviations. So don’t standardize what you don’t need to.
The absence of a standard can be a problem. I remember a 2-in binder of specs on how to inspect an aerospace part that did not actually contain objective criteria for rejecting a part.
More generally, Standard Work, Job Instructions, Acceptance Specs, etc. are documents that are necessary to ensure a consistent output but not sufficient to guarantee that products will work for customers.
Products that are perfect on our terms may still displease customers, because they are using them in ways we didn’t anticipate. That is a problem, but it is neither the lack of a standard nor a deviation from any standard.
From what you write, I assume that you consider a standard to be an explicit statement of what should be, whether it is expressed as “this bolt should be tightened to x foot-pounds of torque,” or “this bolt should be tightened until the nutrunner’s light goes green.”
There are problems that cannot be expressed as a deviation from standard. As we all know, the proof of a cake is in the eating, which means that it cannot be tested before leaving the pastry shop. You serve this untested cake to your guests and it’s awful. The taste of the cake, in Juran’s terms, is a true characteristic. It is really what you are after but, more often than not, it is something you don’t know how to measure, and you can’t set a standard for.
You can measure some substitute characteristics of the cake, like its diameter, sugar content, or fat content. For these substitute characteristics, you can have specs to deviate from, and, if a cake is out of spec, you know it’s bad. It is, however, possible for a cake to meet all the specs you have defined and still taste awful. Whatever standards you define work as a one-way filter. What they allow you to reject is defective, but you don’t know that what they let through is not.
This was the old debate between Philip Crosby, for whom quality was “compliance to requirements,” and Juran, for whom it was “the agreement of reality with expectancy.” These are different philosophies, leading to different practices. For engineering students, for example, the Crosby approach would equate scoring As on exams with being a good engineer; in the Juran approach, there is more to it.
It is “Standardized Work” that is the questionable translation. The Japanese term is 標準作業 (Hyojun Sagyo). 標準 (Hyojun) means Standard and 作業 (Sagyo) means work. Google translates 標準作業 to Standard Work and Standard Work to 標準作業. If you translate “Standardized Work” into Japanese, you get 標準化された作業 (Hyojunka sareta sagyo) and more syllables on both sides. I prefer the shorter version.
The same concept is called “Standard Work” by Ohno, “Standard Operations” in the JMA’s ‘Kanban, Just-in-Time at Toyota” and in Monden’s “Toyota Production System,” and “Standardized Work” in the LEI Lean Lexicon and on the Toyota Georgetown website.
If the terms were intended to designate different things, they should be more distinctive. I actually don’t think either one makes much sense because they are too generic and not descriptive. If you hear “page scanner” for the first time, you guess accurately what it does; for “Standard Work” or “Standardized Work,” good luck! Everybody thinks they know what it means, but all interpret it differently, which does not help communication.
David Hayden brought up the subject of Standard Work for leaders, managers, and engineers. I see all jobs as routinely involving a mix of the following:
- Repetitive tasks
- Planned responses to events
- Decision making in the face of unplanned events.
For production operators, it is mostly repetitive taks; for CEOs, mostly decision making. Standard Work, if defined as the combination of takt time, work sequence and standard inventory, is only applicable to production operators. In a broader sense, it can be applied to all repetitive activities.
A team leader in a cell, for example, does production work for about 50% of the takt time, and, in addition, is responsible for
- Maintaining the pace.
- Relieving other team members as needed.
- Supplying materials and tools to other team members.
- Keeping records.
- Coordinating changeovers.
- Coordinating 5S at the end of the shift.
Planned responses are not Standard Work in the strict sense. As far as I know, within Toyota in the US, they are organized under “Change Point Management” (CPM). In Japanese, as Casey Ng pointed out, it is called 変化点管理 (Henkatenkanri). About the scope of CPM, he wrote:
“For change point management such as a change in takt time , the introduction of new members to a line, preparation to shut down, startup after week-end, resuming production after a power failure, introducing a new product, changing of new version of parts etc. There are all sort of standards which may generally call Standard Work.”
Len Canoot asked whether the elements of Standard Work were translatable to project management.
The time it takes to do the work is the process time or the cycle time, not the takt time. In a line that works at a steady pace, the takt time is the interval between consecutive unit completions in order to meet the schedule within the work time available.
Does it translate to projects? It depends what kind of projects. If all your projects are “Kaizen events,” each one takes 11 weeks: 6 weeks of preparation, 1 week of focused activity, and 5 weeks of follow-up. It is a standard process, and you can to run them at fixed intervals in different areas of your plant. Most projects, however, are not reducible to this kind of cookie-cutter approach.
In a more general setting, there are tools you can use to manage a flow of projects, like capping the number in progress, so that participants’ attention is not spread too thin. At the very least, all your projects are either waiting to start, in progress, or finished. Often, however, they all go through a more detailed, common sequence of phases through which you can track them, even though the work required for a project through a given phase may vary.
Does that add up to standard work for projects?
About the usual meaning of standard, this is what Wikipedia says about technical standards:
“A technical standard is an established norm or requirement in regard to technical systems. It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes and practices.”
That covers the metric system and the internet protocols. Wikipedia also says the following about Standard Operating Procedures (SOP):
“In clinical research, the International Conference on Harmonisation (ICH) defines SOPs as ‘detailed, written instructions to achieve uniformity of the performance of a specific function’.”
When I see “detailed, written instructions,” it makes me think of the victorian-novel sized instruction binders that sit on shelves in many plants, unread, dusty, and full of obsolete information. Standard is also used in many other ways.
Anders Penker brought up the issue of the effect of changes in pace on Standard Work. One key reason you set up U-shaped cells, with the operator work area inside, is staffing flexibility. If it takes, say, 5 operators to operate at capacity, you can operate with 3, 2 or 1 operator at reduced rates, as seen below:
Of course, your work chart and work combination chart for 6 operators are not applicable when you only have 4 or 3. But operating at a reduce pace with fewer people is something you can anticipate and plan for. You should have Standard Work ready for these circumstances, and post it as needed.
And there are circumstances where these charts are not applicable, for example when you apply the bucket-brigade method to make custom-configured products. But that is a different topic.
“As an undergraduate engineering student I spent a term in the offices of a nuclear power company writing standards. I sat at a desk, with a typewriter, and nuclear engineers fed me information while I wrote the standards. Standard 300.47.3.1. I had never been to a nuclear power site and had no idea what I was writing about, and I am pretty certain nobody at the site had memorized the tens of thousands of standards. They were aimed at the Nuclear Regulatory Commission who audited the company so we could prove we were safe. To the best of my knowledge pieces of paper never prevented a nuclear crisis.”
Jeffrey Liker chimes in on the issue of standards. While efforts to clear up the confusion on this topic in the context of Lean are praiseworthy, I think the terminology of “Standardized Work,” and “Work Standards” itself is hopeless.
Every author uses them differently, there is no hope of achieving consistency, and the word “standard” comes with too much undesirable cultural baggage, as illustrated by Jeffrey’s anecdote quoted above. As a result, every discussion of this topic is Tower-of-Babel project review.
Just because Toyota in the US uses terms doesn’t mean we have to, as they often are mistranslations of its own, Japanese terms, which themselves are not necessarily clear.
That’s why I prefer to talk about “work combos” for specifying how different tasks performed at different stations are combined into an operator job that fills the takt time, and “work instructions” for the breakdown of each task into steps with key points.
Then we can reserve the word “standard” for external mandates and internally generated rules and protocols used, for example, in quality problem-solving with suppliers.
See on www.industryweek.com
“Every time you set a standard, you create possibilities for deviations, and the need to respond,” David Meier said. The setting was a presentation on problem-solving at a corporate in-house conference. It struck me as a concise statement of why managers should issue standards only where clearly and unquestionably useful.
Unnecessary standards were discussed in an earlier post, but the topic is worth revisiting in greater detail, first because there are so many of them in companies, making work life more complex than it has to be, and second, to elaborate on their impact on the organization.
Standards are rules set for others to follow, and rarely welcome, particularly when these others are thereby required to change behaviors they consider rational and appropriate, and sometimes more advanced than the standard. If you don’t enforce your unnecessary standard, your hurt the credibility of all your standards, including the useful ones; if you do, you turn into Captain Queeg, as he “tried to run the ship properly, by the book.”
The reception desk in the lobby of the building where the conference took place had a holder full of pens for visitors to sign in. No two pens were alike. A Captain Queeg would have had none of that; he would have mandated a model of pen and a color of ink, and set up regular audits to monitor compliance.
The example David gave was of office 5S zealots in Germany who had marked a location for a computer mouse on an individual’s desk and written him up for not complying. Last year, Mark Graban had posted a similar example of “5S” at a desk in the UK, shown on the right.
It reminded me of my experience of working in a Japanese office in the 1980s. It was a room with about 30 gray metal desks arranged in facing rows without any partitions. Everywhere else I have worked, each desk had its own supplies of staplers, staple-removers, scissors, glue sticks, etc., but it was not so in that office. These were shared resources, stored in a transparent plastic chest in the center of the room, with a label for each compartment.
This arrangement sounds right out of a Staples commercial, but that was the way it was. What struck me about it, however, was that the sharing created the need for labeled locations and for the discipline to return the items to assigned locations after use. This approach might make sense in offices used in hotelling mode. Everywhere else, however, each office worker has a dedicated desk that comes with a set of tools, that the employee organizes as he or she sees fit.
In the 21st century, the tidiness of desks does not have much to do with the performance of an office. What really makes a difference is the way information is organized on its computer network, and that is not visible when you walk through the office. But effective ways to do this are a whole other discussion. In factories, 5S in the offices is sometimes justified “to show solidarity with the shop floor.” It has been suggested to me that a better way to show solidarity might be to make the offices as hot, smelly and grimy as the shop floor.
Sometimes, the consulting companies that guide 5S implementation in client offices do not practice it in their own. In one particular firm, as consultants were in the field most of the time, they had no permanent desk, and grabbed an available one when they happened to be in town. With such a system, you might have expected the rooms to be numbered, and to have a magnetic board at the entrance with token for each present consultant to mark on a map of the facility where he or she could be found, but the managers felt that such a board would have been “ugly.” They never told me why they didn’t number the rooms. To locate a consultant you had to call his or her cell phone, and then follow instructions like “go left at the top of the stairs and it’s the third door to the right.”
Besides the size of steel balls at the end of motorcycle brake handles and company email addresses listed in my earlier post, there are many other things that are better off not standardized, and prominent ones include the analytical tools used in problem-solving.
The institutions of the quality profession in the US still promote as a standard the 80-year old tools of SPC, as if the art of collecting and analyzing data had not evolved since 1930. These tools are obsolete, but it would be a mistake to replace them with another set as a new standard.
There should be no standard. The professionals who work on improving quality should learn to use a broad variety of tools, and should be free to use whichever they think may help in their current circumstances. And they should always be on the lookout for new approaches and new technology.
Likewise, Value Stream Mapping (VSM) has, in the past 15 years, been elevated in the US to the position of a standard that all Lean practitioners are mandated to use. The need to map flows of materials and information in a manufacturing supply chain is often real, but there is no need for it to be done in a specific format with a specific set of symbols.
In fact, what happens in both situations is that formal compliance with the standard rapidly becomes the only criterion against which the outputs of quality or flow improvement teams are reviewed. The tools, their appropriate use, and their range of applicability are understood neither by the teams mandated to use them nor by the auditors who make sure they do, and the result is wallpaper.
In the TPS Principles and Practices discussion group on LinkedIn, Brian Miller initiated a discussion on “How do you create standard work for a customized product that has over a billion combinations?” It has had 31 comments so far, and I would like to share here a few that I made.
Even in a plant that is perceived to be focused on low-volume/high-mix production, you usually have an uneven demand pattern, calling for different approaches to standard work by product category.
You start with a Runner/Repeater/Stranger analysis to determine what it is we do often and what not. Without this analysis, we commingle in the same lines products made every day with other products made sporadically (See Lean Assembly). In Japan, this is called P-Q, or Product-Quantity analysis, with the categories called A, B and C. The more vivid Runner/Repeater/Stranger terminology comes from Lucas Industries in the UK. You then use a dedicated, integrated production line for each Runners, a flexible line for each family of Repeaters, and a job-shop with functional groupings of equipment for Strangers.
Then, obviously, you face different challenges for developing standard work in each category:
- In a runner line, you can post A3 sheets above each workstations with instructions for the purpose of allowing supervisors to monitor how the work is being done. This is the normal situation of high-volume production.The operators themselves do not need to read the instructions for every workpiece; as soon as they are proficient in the job, they work from memory.
- A repeater line is for a family of products with variants but with a high commonality of materials and processes. The instructions that can be posted on A3 sheets are then limited to the common processes, but the operator needs to read what is specific to each workpiece. For final assembly of cars, Toyota has provided “build manifests” printed on larger sheets mounted on car bodies and bearing all the option information. The kitting of workpiece-specific components also helps. In computer assembly, workpiece specifics are shown on electronic displays, with component picks validated by auto-ID technology, including bar codes, QR-codes, or RFID chips.
- Strangers are the odds and ends with sporadic demand, one-of-a-kind systems, or new product prototypes. For strangers, you cannot rely on operator memory or habit. For one-of-a-kind systems or prototypes, you cannot even assume you have the knowledge needed to produce workable detailed instructions. Each stranger is a job in a job shop and requires instructions on a traveller that moves with the workpiece. The traveller may be hardcopy or electronic. An electronic traveller may either be a device containing all the instructions or an ID that triggers the download of appropriate instructions at each station. Strangers are usually built by skilled craftsmen able to work directly from engineering drawings. Given the nature of strangers, however, the time required cannot be precisely known and sequencing mistakes will happen, making rework inevitable.
The articles by Art Smalley‘s and Mike Rother about Standards in The Lean Edge puzzle me, because it seems we all mean different things by “standard.” On a manufacturing shop floor, in particular, I don’t see Standard Work as a basis for comparison, the best way known to perform a task, or a target condition. Instead, it is a set of rules published for the purpose of ensuring that different people perform the same tasks in the same way. This is consistent with the Wikipedia definition of a technical standard.
A process can only produce a consistent output at a consistent pace on different shifts in the same plant, as well as in different plants, if it is performed on the same materials, with the same equipment, and by the same methods. That is what standard work is supposed to accomplish, and it is, for both human and technical reasons, more difficult than meets the eye.
So here are a few thoughts I would like to share on this subject:
When operators on a manufacturing shop floor remain on the same job for years, they come up with their private tricks on how to perform it. They attach “cheater bars” to wrenches, rearrange parts around their stations, and develop the ability to detect anomalies by sight, sound, touch, or smell. By default, as operators perceive this knowledge to be the key to job security, they make sure it remains hidden away in their heads.
It leads to a situation that economist William Lazonick called Craft Control, in which management leaves the organization of work on the shop floor to the operators. The focus of Frederick Taylor’s “scientific management” was to replace craft control with managerial control, and it entailed the detailed specification of all operations by specialists. For decades after Taylor’s death in 1915, the management of American manufacturing companies engaged in a tug-of-war with labor to put an end to craft control, and ultimately failed, resulting in shelves of binders full of specs that nobody pays attention to, except external auditors.
Human resource policies that involved laying off whenever business slows down were an incentive to retain rather than share information. And leaving operators on the same job for years made the specs unnecessary except to train new operators but, when you tried to use them for this purpose, more often than not you found them to be obsolete.
TPS/Lean pursues managerial control too, but in ways that differ as follows:
- Operators are hired for a career in the company and retained through downturns.
- They are frequently rotated between jobs and become multi-skilled, which requires them to share what they know.
- They participate in continuous improvement, leading to the integration of their private tricks into the shared specs.
- Instead of Victorian novels in binders, the specs are concise memory joggers on A3 sheets of paper posted above work stations.
See last July’s post on What are standards for? for examples and details. These differences do not make it easy to implement, but they remove the key obstacles that account for the earlier failure.
A3 instruction sheets above work stations help supervisors notice discrepancies between the standard and the practice of the operators. When there is such a discrepancy, however, the supervisors must investigate it rather than always “retrain” the operator to conform to the standard. The operator may in fact have improved the process; this improvement needs to be documented and the standard updated so as to propagate this improvement to all other operators doing the same process. When walking through a shop floor that has such posted instructions, one should check the signature block to see when it was last updated. If it was five years ago, the sheet is useless. In fact, It should have been updated in the last six months.
In The Birth of Lean (p. 9), are Taiichi Ohno’s own words on the subject:
“…the standard work display panels […] let the foremen and supervisors see easily if the operators were adhering to the standard work procedures. […] I told everyone that they weren’t earning their pay if they left the standard work unchanged for a whole month.”
Changing specs once a month for every operation seems a hectic pace, leaving operators barely enough time to master the new method before changing it. Perhaps it was justified in Toyota’s single machine shop, that Ohno was running in the early 1950s. Managing revisions in a network with dozens of factories worldwide that is Toyota today is a different kind of challenge.
Posting too many instructions, maps, charts, forms, before-and-after pictures, etc., is counterproductive. The result is visual clutter rather than visual management. Producing, posting, and maintaining displays is work, and it should be done selectively, when it has a clear purpose and is worth the effort.
In daily life, we use complex products like computers, cars, or kitchen appliances without posted instruction sheets. We can, because these products have been engineered for usability and mistake-proofed. Usability engineering is the art of designing human-machine interfaces so that users find the right actions to take without prompting or instruction; it is widely applied to household appliances, based on techniques described in Don Norman’s The Design of Everyday Things. In Taming HAL, Asaf Degani expands on these techniques for application to airliner cockpits and ship control rooms, and Chapters 1 and 2 of Working with Machines summarizes them as they apply to production equipment. Usability engineering is about making mistakes unlikely, but not impossible; this is why, whenever possible, it is supplemented by mistake-proofing. The following pictures illustrate one of the usability engineering principles. In Pixar’s “Lifted,” the young alien taking a test cannot tell which switch to press; Don Norman shows an example of a control room in a nuclear power plant where technicians have replaced identical joysticks with different beer keg handles to make them easier to tell apart.
Toyota in recent years has been pursuing a reduction in the amount of information posted on the shop floor. They simplified the tasks to eliminate the need for posted instructions, which also made it easier to train new people. This has been going on in several plants worldwide for several years, resulting in continuing improvements in quality and productivity. Instruction materials are kept off line and brought out as needed, like a car’s owner manual.
Employees talk about “Lean Manufacturing,” and what it means to them. They talk about continuous improvement, and participating in events, but what do they have to show in terms of changes made to operations? What they discuss most is 5S, and second to that is standard work. The say nothing of setup time reductions, improvements in flow, pull systems, mistake-proofing, or equipment modifications.
No numbers are given about achievements. The customers find the plant appealing, which is good marketing, They say they have reduced costs and improved quality, but they don’t say how much for either. The only number quoted is that an employee was able to cut his lawn mowing time at home from 3 hours to 2 by better planning his mowing route, using what he had learned at work.
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