Apr 8 2013
Lean efficiency pays dividends | Packaging Digest
See on Scoop.it – lean manufacturing
See on www.packagingdigest.com
Apr 7 2013
The Truth about Lean Failures | Vivek Naik
See on Scoop.it – lean manufacturing
The truth is, most lean implementations are a failure over long duration.Some of them are the major causes, as identified by the people involved in the implementation. They may be the right or maybe these are just the symptoms.
Michel Baudin‘s insight:
In this post, Vivek Naik presents the results of a survey about the causes of Lean implementation failures conducted among the readers of his blog.
The respondents, of course, are not representative of anything except a self-selected subgroup of followers of a blog on Lean, but Naik, to his credit, asked open-ended essay questions like:
- What is your Biggest problem to implement lean in your organisation?
- What would help you overcome this challenges?
And he didn’t tally percentages of responses, which would not have been meaningful. What he does is simply list and categorize the causes that the respondents have put forward.
What I find striking in this list is that no one mentioned insufficient mastery of the engineering and management tools of Lean. ‘Lack of understanding” appears only under Culture. What about the ability to achieve SMED, generate heijunka schedules, or design a bonus system that supports improvement without turning employees into bounty hunters?
Along with the majority of Lean implementers in the US, Naik’s responders take the tools for granted. In that attitude, I see a major cause of Lean failures.
See on viveknaik.net
Apr 5 2013
How Toyota brought its famed manufacturing method to India | The Economic Times
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“…Nakagawa, who has been a TPS practitioner for four decades, doesn’t believe in seeing things on his computer screen -he prefers to go where the action is. “Can a computer smell? Genchi Genbutsu is very important because only on-site will your sensory organs be alert – smell, sound, vision,” he says….”
Michel Baudin‘s insight:
Perhaps, Mr, Nakagawa has not heard of Google Nose, the app announced on April 1.
In all summaries,TPS has two pillars, but never the same. In this article, the pillars are “respect for people” and “continuous improvement.” To Ohno, they were Just-in-time (JIT) and Jidoka, with JIT covering production control, logistics, and supply chain management, while Jidoka was a complete approach to the engineering of production lines where humans interact with machines.
You could try to implement Ohno’s JIT and Jidoka without respect for people or continuous improvement, but it would not work well. Conversely, if all you focus on is respect for people and continuous improvement, you won’t get TPS either. You need both, and, perhaps, two pillars are not enough.
Broadly speaking, the two pillars in this article are about management; Ohno’s pillars, about technology. As TPS is based on the interplay of management and technology, perhaps these are its real “two pillars.”
See on economictimes.indiatimes.com
Apr 5 2013
Is the Kanban system to ensure availability of materials or to reduce inventory?
Pranay Nikam, from VCT Consulting India, asked the following question:
“I have designed and implemented the Kanban System at various type of industries. The challenge I face now is not that of explaining people how the system is designed or how it works. But rather clearing the misconception/misunderstandings key industry people have about Kanban.
My understanding of a Kanban System is ‘A Consumption based replenishment system’ with Multiple Re-Order Point (multiple Bins) as opposed to the traditional Two Bin System. In simpler words you keep enough stock to cover for the total lead time and add a buffer for demand variation and supply failures. And keep replenishing the stock as and when you consumes. The replenishment can be through fresh production or withdrawal from Warehouses or procurement from supplier.
Prime objective of the Kanban System is material availability to enable High Mix and low volume production; ultimately to support production levelling instead of running huge batches.
However, some Lean Consultants propagate Kanban as a inventory reduction tool and nothing more than a material scheduling software that can be configured in any ERP Systems.
I would be happy be receive your comments on the two different perspectives.”
The Kanban system has many variants, discussed in Chapters 10 to 13 of Lean Logistics. All these variants, however, have the following characteristics in common:
- They implicitly assume the demand for an item in the immediate future to match the recent past. It is a naive forecast, but hard to beat on intervals that are negligible with respect to what Charlie Fine calls the clockspeed of the business. And the fluctuations are smoothed by leveling/heijunka.
- They use some form of tokens to signal demand. Whether these tokens are cards or electronic messages, they can be detached from bins and parts and processed separately, in ways that are not possible, for example, in the two-bin system.
- There is a fixed number of tokens in circulation for each item, which is a key control mechanism for the supply of this item.
- The protocols for handling these tokens provide unambiguous directions on what should be done. No human judgement call is required to decide which item to move or produce. There are variations where that is not the case, like the French Kanban, which, for this reason, I don’t consider genuine.
The Kanban system is not just a multiple-bin system, because bins are not used as pull signals. The Kanbans are pulled from bins when you start withdrawing parts from it, which you couldn’t do if the bin itself were used as a signal. If the signals are cards, you can organize them in post-office slots or on boards, which you also couldn’t do with bins. And, of course, you can do much more with electronic signals, which does not necessarily mean you should.
Your description of Kanban omits the goal of keeping inventory as low as you can without causing shortages, and experimenting with the numbers of Kanbans in circulation to test where the limit is, which makes it a tool to drive improvement.
Kanbans work for items consumed in quantities that have small fluctuations around a mean, which means medium-volume/medium mix rather than low-volume/high mix. You use other methods for different demand patterns, like reorder point for bulk supplies, consignment for standard nuts, bolts and washers, or just-in-sequence for option-specific large items… In low-volume/high-mix production you have many items that you cannot afford to keep around and only order from your supplier when you have an order from your customer; it isn’t the way the Kanban system works.
You can do many things with ERP systems but, historically, they have been more effective in managing purchase orders with suppliers than in directing shop floor operations. If you have an ERP system with accurate, detailed data about your shop floor, you can, in principle apply any algorithm you want to produce a schedule. Most ERP systems, however, do not even have structures in their databases to model the behavior of production equipment at a sufficient level of detail, and are not capable of producing actionable schedules. They print recommendations, and the final decision on the work that is actually done is a judgement call by the supervisor, or even sometimes the operator. Within its range of applicability, the Kanban system avoids this with simple rules, by focusing on what is actually observable and controllable at the local level.
So, I suppose the answer to your question is that the Kanban system’s immediate purpose in daily operations is to assure the availability of materials while reducing inventory, with the longer-term purpose of driving improvement. Pursuing either of these goals at the expense of the other would be easier but not helpful to the business.
Apr 4 2013
The Purpose of Standard Work in Manufacturing
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:
Standard Work versus Craft Control
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.
Use of A3 instruction sheets
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.
Avoiding Lean Wallpaper
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.
Apr 9 2013
Flow improvements called “5S” at Avanzar | Jeffrey Liker
See on Scoop.it – lean manufacturing
“Recently I revisited Avanzar, Toyota’s interior and seating supplier for their San Antonio, Texas truck plant. Most major suppliers are on-site delivering directly to the factory which in the case of seat assembly is right across a wall. Avanzar’s CEO, Heriberto (Berto) Guerra, was very excited about their Japanese advisor, formerly of Toyota, and all he had been teaching them about real kanban. I had visited a year earlier and Mr. Guerra was very excited about their Japanese advisor, formerly of Toyota, who was teaching them kanban. A year before that, he said they were making progress in a few model areas and now there was kanban everywhere. Mr. Guerra also raved about the way their advisor was teaching them 5S, which again I found confusing.”
A well-documented case of Lean implementation at a just-in-sequence supplier ot seats to Toyota’s plant in San Antonio, TX. An oddity of this case is that they lump under the “5S” label all sorts of changes that are well beyond it, such as redesigning part presentation at assembly to make frequently used items easily accessible, or kitting parts.
Of course, as long as it works for them, they can call it whatever they want. For communication with the rest of us, however, as Jeffrey found, it is confusing.
See on www.manufacturingpulse.com
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By Michel Baudin • Press clippings • 2 • Tags: 5S, 94306, Just-in-sequence, Kanban, Lean, Lean manufacturing