Lean Vocabulary Words

The "S's" are named for 5 Japanese words, beginning with the "S" sound. In English they are: 1) Sort, 2) Set in Order, 3) Shine, 4) Standardize, & 5) Sustain.

For more information, please see the section called 5S.

For example, assume we're making automobile pistons, and our tolerance specification is +/- 0.0002 inches on the diameter. A 6-sigma capable process for grinding the cylinder diameter would ensure that no more than 3.4 cylinders in every million are outside this tolerance (when under "normal" manufacturing processes.).

6-Sigma methodology, abbreviated by the acronym DMAIC (Define, Measure, Analyze, Improve, and Control) is a fairly rigid framework for identifying, analyzing, and improving the process to reduce variation. It utilizes a large number of sophisticated statistical tools to determine what creates variation, and this allows us to then development countermeasures to reduce it.

Lean and 6-Sigma (often abbreviated LSS) are separate, but highly complementary disciplines.

For more information, please see the section called 6-Sigma.

The wastes are: 1) Defects, 2) Overproduction, 3) Waiting, 4) Inventory, 5) Extra Processing, 6) Conveyance, & 7) Motion. In addition, I always add the most important form of waste: 8) Unused Human Ingenuity.

One key Lean concept is that waste has to be identified before it can be eliminated. In fact, you often find that people often go to extraordinary efforts to hide waste.

Lean tools try to make waste glaringly - even painfully - obvious. It is only by recognizing this waste that we have a chance of eliminating it.

For more information, please see the section called The 7 Deadly Wastes.

Andon cords were popularized by Japanese automobile manufacturers who found that their assembly lines ran more smoothly if each assembly worker had the authority to stop the line. This meant that problems were dealt with quickly rather than being allowed to fester for a long period of time.

A Black Belt is also considered a permanent trainer and mentor to others in the organization. He should be constantly explaining and helping other to utilize the Black Belt tools.

Unfortunately, there is no governing body that establishes credentials for a Black Belt. Several large professional organizations, such as the Society of Quality Engineers, and the Society of Manufacturing Engineers, have established certification procedures that appear to be very good. However, this means you can never be sure how much a "Black Belt" really knows unless you test him.

We would like for Buffer Stock to be as small as possible. In a perfect world, this stock would be zero. As a process becomes better and reduces these types of variation, it is possible to reduce the buffer stock.

Buffer Stock is very similar to Safety Stock, except that it is kept to allow for minor variations in the supply chain instead of catastrophic events such as missed supplier deliveries or major machine malfunctions.

People often find that the most of the work of a changeover proceeds quickly, but the process needs a lengthy series of adjustments and trial runs before a good piece is finally made.

SMED principles are often used to reduce changeover time.

The project charter includes a formal definition of the problem (which is surprisingly difficult to write), as well as a justification for doing the project. It also will outline the expected completion dates, and the resources (both capital and human) needed.

One major portion of the charter is the "Scope". The scope defines what is included in the project, and more importantly, what is not included. Projects often suffer from "scope creep" where the boundaries of the work expands during the course of executing the project. When this happens, it makes it much more difficult to complete the project on time with the allocated resources. A well defined scope, agreed to by management, makes this creep much less likely.

Ideally, Cycle Time should exactly equal Takt Time. However, in the real world, we want the Cycle Time to be slightly shorter than the Takt Time so that any disruptions in our internal processes do not impact the customer and leave him without product.

The goal for each hour is adjusted based on the product being run and the actual working time for that hour. Therefore the goal is half the normal rate for the hour where the associate gets a half-hour lunch break.

Managers must regularly and publicly review the board. They praise the associate if they meet or exceeded the goal, and do troubleshooting to find out why the goal was not met.

This system prevents the "lost hour" phenomenon where a problem slows production for an hour or more and no one knows the problem is occurring.

The use of the board itself can improve productivity by over 10%.

For more information, please see the section called Day-by-the-Hour Boards.

You can download an short training course on Day-by-the-Hour boards here.

In a Lean world, we detest the "Deadly Waste" of Processing. Every hour spent reworking products saves a few products for that day. But every hour preventing rework by solving the root cause pays off forever.

Don't fall into the rework trap! Spend your energy finding the root cause of problems and solving them.

The managers are able to see the operating results (from the Visual Metrics) and they can offer praise, advice, or direction to operating associates.

Gemba walks have 3 profound benefits:

1. Managers get out of the office and really find out what's happening. They become truly involved in a way that they may not otherwise.
2. They martial all the available resources needed to quickly solve routine problems.
3. They allow the management team to be seen as interacting and being involved.

For more information, please see the section called Gemba Walk.

Unfortunately, there is no governing body that establishes credentials for a Green Belt. That means you can never be sure how much a "Green Belt" really knows unless you test him.

The next higher level is Black Belt.

Heijunka boxes provide many great benefits. They are simple and visual; they put final scheduling control at the operation; they are very flexible.

The name comes from the classic book "The Goal" by Goldratt. In the book, the Hero is leading a troop of boy scouts on a hike, and discovers that the entire troop's progress is held back by Herbie, the slowest hiker of the troop. The Hero discovers that it does not matter how fast any of the other scouts can hike, the entire troop will be held back by the slowest boy (the "Herbie").

Manufacturing engineers often fall into the trap of trying to speed up all the operations in a value stream, when in fact, only the bottleneck's (the "Herbie") production rate will actually have a profound effect on output.

The words are Japanese for the needle of a compass and for managerial control. (Think of a fleet of old ships, with all their compasses pointed north, all moving in the same direction.)

Hoshin Kanri is therefore how management sets an overall direction, and the entire organization strives to move in that direction on a daily basis.

Some organizations use the obtusely named "Policy Function Deployment" to achieve this same objective.

Kaizen Blitzes have a very specific methodology which involves training associates, executing the improvements, and then presenting those improvements to the rest of the organization.

A Blitz will typically last 3 - 5 days, although very small, focused blitzes can be done in just a few hours.

For more information, please see the section called Kaizen Blitz.

A visual Kan Ban can also be an integral part of a Visual Factory.

6-Sigma methodology is based on the DMAIC process.

For more information, please see the section called 6-Sigma.

Our objective is not to equalize the load on everyone. Instead, it is to fully load (but not overload) as many people as possible and create large blocks of idle time which we may use to reduce headcount or fill with other value-added work.

He is a Black Belt with extensive and wide experience in using Black Belt methodology. Some people believe a MBBs knowledge should be "deep", while others believe that a breadth of knowledge and ability to apply LSS methodology to a wide variety of real work problems truly defines the Master Black Belt.

Like the other belts, no governing body exists which establishes credentials for a Master Black Belt.

OEE = (% Speed) * (Quality Yield %) * (Uptime %)

Percent of Full Speed refers to the current speed of the machine compared to the speed of a machine in perfect operating condition. If wear on the machine has forced the machine to be run slower so that it makes good product, then this percentage is reduced.

Quality Yield is the percentage of good products made on this machine. Defects caused by poor materials or operator errors should not count, since we are only concerned with the machine itself.

Uptime is the percentage of time the machine runs, when you want it to run. Don't count time the machine is scheduled to be down for maintenance or lack of work.

Organizations often think they have a full machine, but find that due to mechanical wear and tear, they have much less than a fully functional machine. The OEE indicates mathematically what percentage of a good machine you have.

While simple in practice, actually gathering accurate OEE data can be quite burdensome from a record-keeping standpoint. Many organizations short-cut this process and use OEE only as a relative measure of performance. They look for changes in OEE rather than the actual OEE itself. This reduces the value of the calculation slightly, but this trade-off is probably still acceptable if it lets an organization understand how equipment problems are hurting their performance.

Rework is completely anathema to Lean practitioners, and a Poke Yoke system forces us to fix the problem rather than simply "live with it" and do rework.

A common example of a poke yoke in your everyday life is the fuse box in your basement. We would rather have you be greatly unconvinced with a power failure than allow an electrical overload to cause a fire. While the blown fuse is very inconvenient (especially when the big game is on TV!), it is preferable to allowing us to lose our house in a big fire. A blown fuse is absolutely unforgiving; we must fix the overload before we can do anything else.

This unwieldy phrase is similar to the Japanese phrase Hoshin Kanri, for the needle of a compass and for managerial control. (Think of a fleet of old ships, with all their compasses pointed north, all moving in the same direction.)

Some organizations use the Japanese name "Hoshin" or "Hoshin Kanri" to achieve this same objective.

For example, if a company is fabricating metal parts and then does a final painting operation, the fabricating department is prevented from fabricating more parts until the last parts have been painted. This prevents a buildup of parts at the painting operation, and makes the material flow more efficiently through the factory.

Pull systems represent a fundamental change in how an operation is managed on a daily basis. Instead of scheduling each operation to run, and then hoping they run the expected products on time, we schedule a single point in the process, and let the later operations pull products from the earlier operations. In this way, we create a much stronger customer/supplier relationship between sequential operations. We like this customer/supplier relationship because it helps clearly establish requirements and tends to make each more efficient than it would be otherwise.

Pull systems often are part of a Supermarket system.

During a 5S event, people often find valuable items (such as furniture, equipment, or supplies) that are not needed in the immediate area, but might be useful somewhere elsewhere in the organization. Normally, we are ruthless about disposing of unneeded items, and using the Red Tag process allows us to remove them from our workplace while at the same time making sure that someone else doesn't need them.

The Red Tag process works by placing red-colored tags on unneeded items. On the tag we write the name of the person who does not want the object, as well as the date that they tagged it. These items are then moved to a special, public space where everyone can see the items. If anyone else in the organization has a use for a tagged item, they may take it. However, if no one takes the object after 30 days or so in the Red Tag Area, it is disposed of.

For more information, please see the section called 5S.

The stock itself is indistinguishable from Buffer stock, but the reasons for keeping it are due to the things in the "act of God" category instead of the "variation" category.

SMED involves moving tasks from "internal" (when the process is down) to "external" (when the process is still running). In other words, we try to do as much work for the setup as possible while the process is still running, so that we minimize the downtime.

We also work very hard to eliminate adjustments to the process. In our Lean world, we want to install new tooling, change a few dials, and then immediately make good products.

In a supermarket there is a dedicated and limited space for a particular product. Once that product space is filled, no more of that product can be produced until the space is opened up by having a customer remove the product when he purchases it.

The customer can take any product he likes off the supermarket shelf, but the producer can only produce a product if there is a space available to take it. This effectively prevents the waste of of overproduction.

The determination of the amount of space to keep on the shelf can be a complex calculation involving the rate the customers take the product (the Takt time), the production cycle time, and the variability of both.

"Takt" is the German word for "Beat" or "rhythm". It becomes our metronome.

For example, customers log on to your website and purchase 312 Green Widgets and 27 Red Widgets every day. If your Widget factory runs a single 8-hour shift, then the Takt Time for Green Widgets is:

8 * 60
----------------
312 Green Widgets

1.54 minutes / Green Widget

And the Takt Time for Red Widget is:

8 * 60
----------------
27 Red Widgets

17.78 minutes / Red Widget

We therefore want our Widget factory to be able to produce 1 green Widget every 1.54 minutes and 1 Red widget every 17.78 minutes. (If they are made on the same equipment, then our total widget Takt time is 1 widget every 1.42 minutes).

We often have trouble with the Takt time because it changes from hour to hour and day to day due to changes in our sales to the customer. Ideally, we change our production rate to exactly match the Takt Time. If the Takt changes too often, we typically take an average Takt time over some period and match the average. We must always be aware that the Takt can (and will!) change, forcing us to adjust our production rate.

"Value" is anything the customer will pay for.

If the customer is willing to pay you for it, it is valuable. If he is not willing to pay, then it has no value.

For example, we don't put industrial products in expensive, glossy packaging since the industrial customer place no value on anything other than protecting product integrity. Consumers shopping in supermarkets, however, place a great deal of value on "shelf appeal" and are willing (if often unconsciously) to pay for expensive packaging and image branding.

The truly horrifying thing to realize about value is how much of our time we spend doing things our customers do not want to pay for. This gives us great opportunity, however, to minimize those non-valuable things and spend more time doing things he will pay for.

For more information, please see the section called Visual Factory.

For more information, please see the section called Visual Metrics.

One of the most surprisingly difficult aspects to solving a problem is actually defining what that problem really is. People who have trouble defining a problem will also have a great deal of difficulty solving it. WDGLL is part of this problem definition process.

Typically, a Lean project will start with a "Charter" that defines many things, including "the Problem", and its opposite, WDGLL.

A WDGLL must be written in clear, grammatically correct sentences. If you cannot define WDGLL in clear sentences, then you really don't understand what you're trying to do, and therefore, you will never accomplish your goal.