Once at the retail store, the roll cages are taken from the receiving dock to a storage area in the rear or direcdy to the shelves, and the cola is sold in about two days. When the cola is taken home it is typically stored again, at least for a few days, perhaps in the basement if the shopper has bought a number of cartons to take advantage of a special promotional offer.
Then it's chilled and, finally, consumed. The last stepprobably requires about five minutes, after nearly a sear along the stream. A final important step, also shown in Figure 2. Currendy, only 16 percent of aluminum cans in the U. If the percentage of cans recycled moved toward percent, interesting possibilities would emerge for the whole value stream. These activities would suddenly convert from type 1 in our typology—muda but unavoidable—to type 2—muda that can be completely eliminated right away.
The slow acceptance of recycling is surely due in part to the failure to analyze costs in the whole system rather than just for the recycling step in isolation. When laid out this way, action by action, so it's possible to see every step for a specific product, the value stream for physical production is highly thought- provoking.
First, as shown in Table 2. More than 99 percent of the time the value stream is not flowing at all: the muda of waiting.
Second, the can and the aluminum going into it are picked up and put down thirty times. From the customer's standpoint none of this adds any value: the muda of transport. Similarly, the aluminum and cans are moved through fourteen storage lots and warehouses, many of them vast, and the cans are palletized and unpalletized four times: the muda of inventories and excess processing.
Finally, fully 24 percent of the energy-intensive, expensive aluminum coming out of the smelter never makes it to the customer: the muda of defects causing scrap. TABLE 2. DC 0 0 3 days — 8 24 Tesco store 0.
The jump in scrap at the can maker is due to the loss of about 14 percent of the material in the punch. The loss at the bottler is mainly from damaged cans rejected as they are loaded in the filling machinery.
Because the cans are stored empty with no internal pressure, they are easy to damage in handling. The jump in scrap rate at the home of the customer, shown in brackets, is the consequence of recycling only 16 percent of the 76 percent of the original aluminum which reaches the customer. The boats, warehouses, and processing machines we have been describing are truly massive and we can see that the primary objective of technologists in the beverage industry has been to scale up and speed up this equipment while removing direct labor, in a classic application of the ideas of mass production.
Indeed, this machine may be much more expensive than a smaller, simpler, slower one able to make just what the next firm down the stream needs Tesco in this case and to produce it immedi- ately upon receipt of the order rather than shipping from a large inventory. For the moment, let's just reemphasize the critical leap in embracing value stream thinking: Stop looking at aggregated activities and isolated machines —the smelter, the rolling mill, the warehouse, and the can filling machine.
Start looking at all the specific actions required to produce specific products to see how they interact with each other. Then start to challenge those actions which singly and in combination don't actually create or optimize value for the customer. Ordering Cola If it takes days to bring a cola from bauxite to Tesco and a similar amount of time to make most of the other items along Tesco's aisles , there is a clear problem in ordering.
Either orders must be completely uniform over time so the producers all along the stream can operate stable schedules with litde inventory, or the upstream producers must maintain large inven- tories at every stage to deal with shifts in demand, or Tesco's customers must learn to live with shortages.
None of these is desirable because all create muda. It has dramatically reduced "stock-outs" a situation of not having a product the customer wants while also slashing its own in-store and warehouse inventories by more than half. Because Tesco was already one of the most efficient grocers in the world when it started this process, it appears that its current inventories are only half the U.
However, Tesco has recently realized that to move even further in reduc- ing inventories, stock-outs, and costs on a total system basis where more than 85 percent of the costs of a typical product like cola are outside Tesco's corporate control , it -will need to improve responsiveness and ordering accuracy all the way up its value stream, running across seven firms in this particular case. Tesco installed a Point-of-Sale POS bar-code scanningjsvstem in the checkout lanes of all of its stores in the mids.
This permitted each store to maintain a "perpetual inventory" of exactly how much of every item it had on hand and to make more accurate orders to suppliers.
This was possible because every time a customer in the aisle took a carton of cola past the checkout, the system noted this fact along with the recent rate of sales and the number of cartons remaining. Replenishment orders could be auto- matically generated. A few years later, Tesco transferred decision making on what each store would purchase and when from the store manager, who had been ordering direct from each supplier, to a centralized system where Tesco placed orders combined from all stores to suppliers.
At the same time, it opened a dozen Regional Distribution Centers RDCs in England so that suppliers for more than 95 percent of all sales volume the exceptions being milk, sugar, and bread would ship to the RDC rather than the store. Instead of sending a small truck, partially loaded, to each store, each supplier could send a large truck to each RDC and Tesco could send another large truck to the retail store each night. In , Tesco took a revolutionary step for the grocery industry by moving toward daily orders rather than weekly or even monthly for all fresh products and for many long-shelf-life items.
Today, when each store takes inventory at the end of each day, the Tesco ordering system calculates the quantity needed to restore normal stocks plus any special demand likely to be caused by the day of the week, the time of year, the weather, or a sales promotion. After a quick review by the store manger, to check for glitches in the assumptions, this information is dispatched to Tesco's central computer. There, the requirements from all stores in each region are accumulated and orders are dispatched electronically to each supplier during the night.
Thus, orders made by each Tesco store on Monday night result in replenishment goods from suppliers reaching each store before it opens on Wednesday morning,14 effectively creating a twenty-four-hour continuous replenishment system. The system is shown in Figure 2. At the same time, the stocks on hand of the average good in the retail stores plus the RDCs fell from 21 to For "fast movers" like cola, accounting for more than half of Tesco's total sales, inventories at the RDC and the retail store combined are now only 3 to 5 days.
However, as Tesco did this, they learned the limits of what can be accom- plished by one firm alone. Their production methods—with high-speed machines, long changeover times, and large batches—have given them no real choice. Because the bottler cannot get rapid response from its upstream suppliers to changing levels of demand, it con- tinues to order batches of goods at weekly, monthly, or even quarterly intervals in the case of some raw materials.
If Tesco wants to shrink costs and improve the reliability of the 85 percent of the value stream it does not directly control, it's obvious that the upstream firms must collectively rethink their operating methods, and this is how lesco and the Lean Enterprise Research Centre joined forces. While it is still in the early stages, the process of jointly conducting the analysis just described should gradually change Tesco, the bottler, the can maker, the cold roller, the hot roller, the smelter, and the bauxite miner from seven isolated adversaries into a team of collaborators, indeed into a lean enterprise.
Creating Cola The final element in the cola story is the value stream for product develop- ment. Historically, in the grocery business, first-tier suppliers like the bottler or the branded purveyor of goods have been responsible for the great bulk of product innovations and introductions.
Yet only a brief effort to list the activities in the value stream culminating in the launch of a new product raises many questions. Typically, a firm like the bottler is continually looking for new products to defend its current market share, to expand its scope of offerings and justify more shelf space at Tesco , and to substitute products with higher margins for old standbys like cola.
In the industry, the typical product development cycle is about one year and consists of a number of product clinics followed by larger product trials culminating in the decision for a full-scale launch. Although the actual steps involved are very simple and typically involve very little true "research and development," they are conducted sequentially so that if one looks down on a product concept from a bird's-eye view it is quickly apparent that during most of the development period the concept is sitting still, awaiting feedback from the group which conducts the clinics on all of the firm's products or awaiting its place on the schedule of the depart- ment which conducts small-scale market trials for all products.
Simply reducing development time and expense, while highly desirable, will not be enough to have much effect on this value stream, so Tesco has started to rethink the product development process on a more fundamental level in terms of value. Perhaps, just as the individual steps in the value stream are incomprehensible in isolation, customers do not really want to shop for isolated items.
Would it perhaps be better for Tesco and its bottler to joindy undertake the development of the full complement of beverages necessary to keep Tesco customers happy, and for Tesco to develop longer- term relations with its customers so they would not be strangers? Toward this end Tesco has just launched a frequent-shopper program that will gather purchase pattern data on every regular customer and should permit a more coherent value stream in product development. Putting Value Stream Analysis to W o r k Having looked at the specific steps involved in the value stream for oiie specific product, we are ready to put our findings to work more broadly.
Instead, we see a large num- ber of steps in the second category. They clearly add no value—they're muda—and they therefore become targets for elimination by application of lean techniques. Note that in performing this analysis we are not "benchmarking" by comparing Tesco's cola value stream with those of its competitors.
They tend to get distracted by easy-to-measure or impossible-to- emulate differences in factor costs, scale, or "culture," when the really im- portant differences lie in the harder-to-see ways value-creating activities are organized. Our earnest advice to lean firms today is simple: To hell with your com- petitors; compete against perfection by identifying all activities that are muda and eliminating them. This is an absolute rather than a relative standard which can provide the essential North Star for any organization.
In its most spectacular application, it has kept the Toyota organization in the lead for forty years.
However, to put this admonition to work you must master the key techniques for eliminating muda. It all begins with flow. Usually, you make an appoint- ment some days ahead, then arrive at the appointed time and sit in a waiting room. When the doctor sees you—usually behind schedule—she or he makes a judgment about what your problem is likely to be. You are then routed to the appropriate specialist, quite possibly on another day, certainly after sitting in another waiting room.
Your specialist will need to order tests using large, dedicated laboratory equipment, requiring another wait and then another visit to review the results. Then, if the nature of the problem is clear, it's time for the appropriate treatment, perhaps involving a trip to the pharmacy and another line , perhaps a trip back to the specialist for a complex procedure complete with wait. If you are unlucky and require hospital treatment, you enter a whole new world of specialized functions, disconnected processes, and waiting.
If you take a moment to reflect on your experience, you discover that the amount of time actually spent on your treatment was a tiny fraction of the time you spent going through the "process.
You put up with this because you've been told that all this stopping and starting and being handed off to strangers is the price of "efficiency" in receiving the highest-quality care. We've already looked briefly at another service, a trip involving an airline. And most of the time the experience is even worse than the Joneses' family trip to Crete because rather than taking a direct flight you must go through a hub for sortation.
In the end, the time you spend actually moving along the most direct route is likely to be litde more than half the total time required to get from door to door. Yet most travelers put up with this system without dreaming of anything better. Health care and travel are usually called "personal services," in contrast with "products" like VCRs, washing machines, Wiremold's wire guides, and Tesco's beverages. Actually, the major difference is that in the case of health care and travel, you the customer are being acted upon—you are necessarily part of the production process.
With goods, by contrast, you wait at the end of the process, seemingly beyond harm's reach. However, there is no escap- ing the consequences of the way the job gets done even if you are not directly involved. Let's take just one example for a common good, the single-family home. Henry Ford dreamed about mass-producing homes using standard but mod- ularized designs with the modules built in factories to slash design and production costs while still providing variety.
A number of entrepreneurs actually created modular designs and briefly set up production lines in the United States to make the modules for prefabricated houses immediately after World War II.
Yet, almost all of the world's new single-family homes are still built largely at the construction site by cutting and fastening a welter of materials to create the basic structure and then installing thousands of individual compo- nents, from plumbing fixtures to kitchen appliances to wall sockets. If you go to your home builder and then to the construction site and take a seat to watch the action, you will mostly note inaction. For example, when Doyle Wilson started to measure what occurred in his office and at the work site as part of his T Q M effort, he discovered that five-sixths of the typical construction schedule for a custom-built home was occupied with two activi- ties: waiting for the next set of specialists architects, cost estimators, bill-of- material drafters, landscape architects, roofers, sheetrockers, plumbers, electricians, landscapers to work a particular job into their complex sched- ules, and rework to rip out and correct the work just done that was either incorrect from a technical standpoint or failed to meet the needs and expec- , tations of the home buyer.
As the buyer at the end of the process, you pay for all the waiting and rework—grumbling, of course—but it is a custom product, after all, and you've heard many stories from your friends about even worse problems with their homes, so you tend to accept the predominant system and its problems as unavoidable and inherent to the nature of the activity. In fact, all of these activities—the creation, ordering, and provision of any good or any service—can be made to flow.
Applying flow to the fall range of human activities will not be easy or automatic. For starters, it's hard for most managers to even see the flow of value and, therefore, to grasp the value of flow.
Then, once managers begin to see, many practical problems must be overcome to fully introduce and sustain flow. However, we do insist that flow principles can be applied to any activity and that the consequences are always dramatic.
Indeed, the amount of human effort, time, space, tools, and inventories needed to design and provide a given service or good can typically be cut in halfvery quickly, and steady progress can be maintained from this point onward to cut inputs in half again within a few years. The Techniques of Flow So, how do you make value flow? The first step, once value is defined and the entire value stream is identified, is to focus on the actual object—the specific design, the specific order, and the product itself a "cure," a trip, a house, a bicycle —and never let it out of sight from beginning to comple-.
The third step is toTrethink specific work practices and tools to ehminate backflows, scrap, and stoppages of all sorts so that the design, order, and production of the specific product can proceed continuously. In fact, these three steps must be taken together.
Most managers imagine that the requirements of efficiency dictate that designs, orders, and products go "through the system" and that good management consists of avoiding variances in the performance of the complex system handling a wide variety of products. The real need is to get rid of the system and start over, on a new basis. To make this approach clear and specific, let's take as a concrete example the design, ordering, and production of a bicycle.
You will not be distracted by novel product designs or exotic technologies. We've also chosen it because we happen to know something about the bicycle industry, one of us having resolved to test the methods we describe in this book by taking an ownership position in a real bicycle company.
Finally, we have chosen bicycle manufacture because it is a deeply disintegrated industry, with most final-assembler firms making only the frame while buying the components—wheels, brakes, gears, seats, handle- bars, plus raw materials in the form of frame tubing—from a long list of supplier companies, many larger than the final assemblers themselves. The problems of value stream integration are present in abundance.
DESIGN Product design in the bicycle industry was historically a classic batch-and- queue affair in which the marketing department determined a "need," the product engineers then designed a product to serve the need, the prototype department built a prototype to test the design, the tooling department designed tools to make a high-volume version of the approved prototype, and the production engineering group in the manufacturing department figured out how to use the tools to fabricate the frame and then assemble the component parts into a completed bike.
Meanwhile, the purchasing department, once the design was finalized, arranged to buy the necessary component parts for delivery to the assembly hall. A design for a new product, usually only one of many under development at a given time, moved from department to department, waiting in the queue in ea:ch department. Frequently it went back for rework to a previous department or was secretly reengineered at a point downstream to deal with incompatibilities between the perspectives of, say, the tool designers and the.
There was no flow. In the late s and early s, most firms switched to "heavyweight" program management with a strong team leader and a few dedicated team members, but without changing the rest of the system. The product "team" was really just a committee with a staff that sent the great bulk of the actual development work back to the departments, where it still waited in queues. What's more, there was no effective methodology for carrying designs through the system without lots of rework and backflows.
There was, therefore, a bias toward ingenious designs with admirable technical features which customers liked but which failed to return a profit due to excess costs and launch delays. The lean approach is to create truly dedicated product teams with all the skills needed to conduct value specification, general design, detailed engineering, purchasing, tooling, and production planning in one room in a short period of time using a proved team decision-making methodology commonly called Quality Function Deployment QFD.
Because every team in a firm also follows this ap- proach, it's possible to accurately measure throughput time and to continu- ally improve the design methodology itself.
With a truly dedicated team in place, rigorously using QFD to correctly specify value and then eliminate rework and backflows, the design never stops moving forward until it's fully in production. The result, as we will demonstrate in the examples in Part II, is to reduce development time by more than half and the amount of effort needed by more than half while getting a much higher "hit rate" of products which actually speak to the needs of customers. A host of narrowly skilled specialists are not needed because most marketing, engineering, purchasing, and production professionals actually have much broader skills than they have 1 ever real- ized, 2 ever admitted, or 3 ever been allowed to use.
When a small team is given the mandate to "just do it. They do the iob well and they enjoy it- Moving most of the employees formerly in marketing, engineering, and production groups into dedicated teams for specific products does create problems for the functional needs of each firm along the value stream, a point we will address in Part III.
Similarly, the need to include employees of key component and material supply firms as dedicated members of the product team raises difficult questions of where one firm stops and the next begins, the second major topic of Part III.
When the orders are fully processed—to make sure that they are internally consistent and that the buyer is credit-worthy—they are sent to the Scheduling Department in Operations or Manufacturing to work into the complex production algo- rithm for a firm's many products. A shipment date is then set for communi- cation back to Sales and on to the customer. To check on the progress of orders, particularly in the event of late delivery, the customer calls Sales, which then calls Scheduling. When orders are really late and important customers threaten to cancel, Sales and Sched- uling undertake some form of expediting by going directly into the physical production system in both the assembler firm and the supply base to move laggard orders forward.
This is done by jumping them to the head of each queue in physical production. Under the influence of the reengineering movement in the early s, a number of firms integrated Sales and Scheduling into a single department so that the orders themselves can be processed much more quickly—often by one person tied in to the firm's electronic information management system so that orders never need to be handed off, placed in waiting fines, or put down. They now flow.
As a result, orders can be scheduled for production in a few minutes rather than the days or even weeks previously required; at the same time, order information can be transmitted electroni- cally to suppliers. Similarly, expediting procedures are tightened up to elimi- nate the confusion which often arose between Sales and Scheduling.
These innovations certainly helped, but a fully implemented lean ap- proach can go much further. And because there are no stoppages in the production system and products are built to order, with only a few hours elapsed between the first operation on raw materials and shipment of the finished item, orders can be sought and accepted with a clear and precise knowledge of the system's capabilities. There is no expediting.
A key technique in implementing this approach is the concept of takt time,3 which precisely synchronizes the rate of production to the rate of sales to customers. For example, for a bicycle firm's high-end titanium- framed bike, let's assume that customers are placing orders at the rate of forty-eight per day.
Let's also assume that the bike factory works a single eight-hour rshift. The point is always to define takt time precisely at a given point in time in relation to demand and to run the whole production sequence precisely to takt time. In the lean enterprise, the production slots created by the takt time calcu- lation—perhaps ten per hour for high-end bicycles for a takt time of six minutes and one per minute for low-end models for a takt time of sixty seconds —are clearly posted.
This can be done with a simple whiteboard in the product team area at the final assembler but will probably also involve electronic displays often called anion boards in the assembler firm and electronic transmission for display in supplier and customer facilities as well.
Complete display, so everyone can see where production stands at every moment, is an excellent example of another critical lean technique, transpar- ency or visual control.
These methods produce periodic surges in orders at the end of each bonus period even though underlying demand hasn't changed and an occasional "order of the century" drummed up by a bonus- hungry sales staff, which the production system can't possibly accommodate.
Both lead to late deliveries and bad will from the customer. In other words, they magically generate muda. Over time, higher-speed machines with higher levels of automation were developed for tasks ranging from cutting and bending to welding and painting.
Assembly lines were also installed to assemble a mix of high-volume models in dedi- cated assembly halls. All bike makers produced a wide range of models using the same produc- tion equipment, and part fabrication tools typically ran at much higher speeds expressed as pieces per minute than the final assembly line'.
The typical final assembly plant layout and materials flow looked as shown in Figure 3. After nearly a hundred years, these manual scheduling methods were replaced in the s by computerized Material Requirements Planning systems, or MRPs. A good MRP system was at least 99 percent accurate in keeping track of inventory, ordering materials, and sending instructions to each department on what to make next. As a group, these systems were a clear improvement on older manual systems for controlling batch-and- queue operations and became progressively more complex over time.
Even- tually capacity planning tools were added to evaluate the capacity of machines at every step in the production process and to guard against the emergence of bottlenecks and capacity constraints. MRP, however, had a number of problems. As a result, downstream manufacturing operations often had too many parts the muda of overproduction or too few parts to meet the production schedule producing the muda of waiting.
A worse problem was that total lead times in batch-and-queue systems were usually quite lengthy—typically a few weeks to a few months between the point in time when the earliest upstream part was produced and the moment when a bike containing that part was shipped to the retailer. How do we measure competence in systems thinking?
As an instructional tool, models can transform the student experience from the static into the dynamic, the flat to the 3D, and siloed to integrated. The contents of this guide reflect our collective interests and experiences using models and modeling in our classrooms for more than a decade. Initially, modeling provided a way for us to step away from multiple choice and toward assessments that more closely reflect authentic scientific practice.
Modeling has become an approach for how we deliver instruction and a method for introducing and connecting new ideas. We have found that modeling activities make us mindful to demonstrate links between ideas and avoid the expert blind spot.
We are more careful to communicate our thought processes, making them more accessible to students learning the material for the first time. We make concerted efforts to specify relationships in material covered, avoid making leaps between steps, and create opportunities for students to do the same. Through modeling, we can see how students approach the material of our courses and then give feedback to address deficiencies. Modeling is now an indispensable and nonnegotiable component of our instruction.
While the research on modeling in undergraduate biology continues to grow, we believe there is strong support for including modeling as part of undergraduate biology instruction. In our experiences, we have seen students use modeling techniques from our classrooms to study for other, non—model based classes and develop research plans. We propose that modeling should be incorporated throughout a curriculum to help students understand the profound role that models play in our discipline and to encourage them to use models for purposes well beyond our classrooms.
Ultimately, the goal of this guide is to help you, our fellow instructors, incorporate modeling into your classrooms in ways that serve your specific needs. Whether it is helping your students externalize their thinking, practice quantitative reasoning, predict and explain system behaviors, or evaluate their understanding of foundational biological processes, modeling is a flexible and valuable tool for accommodating myriad instructional goals. Wilson et al. This article is distributed by The American Society for Cell Biology under license from the author s.
It is available to the public under an Attribution—Noncommercial—Share Alike 3. Kristy J. Tammy M. Jennifer L. Louis, MO Search for more papers by this author. View PDF. Add to favorites Download Citations Track Citations. Abstract As an instructional tool, models can transform the student experience from the static to the dynamic, the flat to the 3D, and the siloed to the integrated. Using 3D printed physical models to monitor knowledge integration in biochemistry.
Chemistry Education Research and Practice , 19 4 , — Google Scholar Bergan-Roller, H. Discovering cellular respiration with computational modeling and simulations. Course Source , 4 , 1—8. Google Scholar Ceballos, V. Model building and a definition of science.
Histories and Cultures of Tourism. Histories of American Education. The Liberty Hyde Bailey Library. New Netherland Institute Studies. The Northern Forest Atlas Guides. Brown Democracy Medal Books. Cornell Studies in Money. Cornell Studies in Classical Philology. Myth and Poetics II. Persian Gulf Studies. Religion and American Public Life. Religion and Conflict. New Japanese Horizons. Zona Tropical Publications. Cornell University Press.
Comstock Publishing. ILR Press. Northern Illinois University Press. Three Hills. By learning in groups, we also learn about the cultures and values of others. By seeing how these unique perspectives influence the learning process, we gain a greater understanding of what we learn as well as each other.
For access to all Making Learning Visible resources on this website as used to be accessible from the original MLV website , click here. Inspired by the innovative educational philosophy that originated in Reggio Emilia, a small city in Italy, Visible Learners offers research-based practices for fostering learning in groups through documentation. In this approach, first developed during a long-term collaboration between researchers at Harvard's Project Zero and Reggio educators, learning becomes a visible activity that develops students' intellectual capacities as well as their individual and group identities as learners.
Visible classrooms can be identified by five key principles—that learning is purposeful, social, representational, empowering, and emotional. The authors define each principle using illustrative learning portraits, quotes from students and teachers, pictures, reflections, and examples of student work.
Additionally, the authors offer teachers and administrators practical ways to enhance learning by increasing collaboration and critical thinking across grade levels and subject matter. Also included is a section containing dozens of tools for making learners and learning visible, incorporating guidelines for the classroom and the staffroom as well as ideas for engaging students' families.
Visible Learners shows how observing and documenting learning can change the nature of that learning, and asks teachers to look beyond surface to understand who their students are, what they come to know, and how they come to know it. ISBN: This book reports on a collaboration between Project Zero and the Municipal Preschools and Infant-toddler Centers of Reggio Emilia, Italy, on the nature of learning in groups and how to understand, support, document, and assess individual and group learning.
The authors argue that systematic and purposeful documentation of the ways in which groups develop ideas, theories, and understandings is fundamental to the meta-cognitive activity that is critical to the learning of individuals as well as groups. The Wheelock Documentation Studio : The Wheelock Documentation Studio is a space for educators to learn about, develop, and exhibit documentation from a variety of learning contexts.
Reggio Children : International Center for the Defense and Promotion of the Rights and Potentials of All Children — is a mixed public-private company established in on the initiative of Loris Malaguzzi and a group of local citizens. Reggio Children also manages the educational and cultural exchange initiatives between the municipal early childhood institutions of Reggio Emilia and educators and researchers from around the world.
Documentation collected for this purpose helps teachers stay close to students' learning and interests by enabling them to revisit a learning experience.
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