Lean FAQ
What is Lean?
Lean production is aimed at the elimination of waste in every area of production including customer relations,
product design, supplier networks and factory management. Its goals are to:
use less inventory, less space, and less time
become highly responsive to customer demand
produce top quality products in the most efficient and economical manner possible.
What is Lean Operations?
Lean Operations in its purest form is the elimination of waste in a process.
What is Business Lean Manufacturing Initiative?
In today’s competitive environment it has become more important than ever to continuously improve our
operations and be as efficient as possible. This will allow Business to continue to grow and win new customers.
One demonstrated way to improve our operations is through the application of Lean production techniques. The
Lean Manufacturing Initiative will use Lean based tools, techniques and resources to improve Business’s
production and servicing processes.
Why is it often called Lean Manufacturing?
It was only by accident that Lean began in manufacturing and took than name. It’s easier to trip over waste there
than most anywhere else.
How should be Lean implemented at business?
Lean is an evolutionary process where process improvement and the sophistication of the tools applied increases
over time. The following is a graphical depiction of this evolution:
The Lean Journey
Control the Process
Tool Sophistication
Single Piece Flow
Reduce Variability
Late Point
Configuration
Kanban Pulse
Stop the Line at Defects
Moving Line
3P
Set Up
TPM
Reduction
Returnable Cont.
Pull Production
Takt Time
Cellular Layout
Expose the Waste
Standard Work
Supermarket
Kitting
Level Load
7 Types of Waste
Assessment Matrix
Value Stream Mapping
5S
7 Ways
Visual
Management
Time / Cultural Maturity
Improvement:
RIP
Inventory
WIP
Inventory
Span
5
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How does Lean differ from Six Sigma?
Though different, Lean and Six Sigma are fully complimentary. Six Sigma is based on the use of statistical tools
to reduce product and process defects while Lean uses a set of management and problem solving tools to
eliminate waste. Because Lean and Six Sigma are fully compatible some lean tools will be incorporated in the Six
Sigma Book of Knowledge for BB and MBB training.
How Do 6-Sigma & Lean Tools Relate?
Lean and Six Sigma are complimentary but are not the same. The basic premise of Six Sigma is to reduce or
eliminate defects. The basic premise of Lean is to eliminate waste (defects being one type of waste). The lean
tools are less statistical than Six Sigma tools and there are quite a few tools in the Lean tool set that are not in the
Six Sigma tool set and vice versa. For example, Six Sigma does not describe value stream maps, quick
changeover methodology, 5S, 3P, single piece flow, cellular layout, etc. Lean and six sigma tools working
together should allow us to achieve even better results.
What is advantage for Business having implemented Six Sigma?”
Business with fully implemented Six Sigma is in a better position to implement Lean than most companies,
because Lean builds on Work-Out and Six Sigma. Lean uses the intelligence and experience of our employees –
both hourly and salaried – to improve a process in the way Work-Out did when it was first implemented – when it
was a “town meeting” approach to finding the best idea. But lean cannot bring a process under statistical control
like Six Sigma can, and Six Sigma alone cannot dramatically improve speed.
If it takes the same number of people, where’s the benefit?
Faster cycle times, for one thing, and the increased sales that usually brings. Less inventory, for another, be it
WIP material in a manufacturing location or unbilled labor hours in a repair facility. And don’t overlook the
benefit in cycle efficiency itself. In the table above, if you are an average machine shop with 1% cycle efficiency
(meaning the material spends 99% of the time at your shop waiting for someone to physically add value to it)
there are tremendous advantages – and many opportunities – in cutting some of that waste.
Lean sounds like another word for “fewer people.” Is that true?
Usually not. At IPP it took more people, in fact, but the work was done much faster and with fewer total manhours. One of the Japanese Lean techniques is called mizusumashi, which translates as “water spider.” In the
Japanese job shop environment the water spider is a senior machinist, sometimes working with an apprentice,
who gathers all the tooling and information for a job together with the materials and ensures that the other
machinists have everything they need. Lean often entails a shift in who does what, using the same number of
people.
Because Lean develops a “rhythm,” there are periods of time that people will be available for planned
maintenance (Lean calls it Total Productive Maintenance, or TPM). Because we consider Indirect Labor
undesirable we need to ensure that TPM is truly productive, and control it with Standard Operations.
If you find that Lean requires fewer people because your cycle time is so much better you’d best put those people
on preparing for extra volume because that’s what you’re going to get in this cycle-driven business.
Do you really believe there’s that much waste?
Walk through your shop and count how many people are actually adding value to the part or assembly they are
working on – how many are changing the physical state of the product to bring it closer to what the customer
wants, like applying weld, making chips, wrapping insulation, spraying paint, etc. How many people do you
count moving material, looking for a tool or some information, setting up a machine tool or determining job
status?
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What percentage of people in that snapshot view are actually adding value to the product?
In the lingo of Lean, this is called your cycle efficiency. In most cases your snapshot will be comparable to the
more accurate measurement – value-added time over total lead time. Here’s an eye-opening chart:
Application
Machining
Fabrication
Assembly
Continuous Manufacturing
Business Processes – Transactional
Business Processes – Creative/Cognitive
Typical Cycle Efficiency
1%
10%
15%
30%
10%
5%
World-Class Cycle Efficiency
20%
25%
35%
80%
50%
25%
Action Work Out? What is that?
Action Work Outs, or AWOs are blue jean, get dirty days that both hourly and management personnel enjoy.
Some have a Japanese Sensei (“teacher”) and some are done internally. In both of them several teams of hourly
and salaried people focused on the Lean aspects that will best improve cycle efficiency at that location, focused
on the Center Manager’s goals. Small shops who want to implement Lean prefer to have a small group meet biweekly to identify and address specific issues. It is often the same group as the Grassroots Team assembled for
Culture Change. The methods are typically low tech and low buck – quite a change from my last job where the
digitization team was always looking at how technology might solve the problem.
Isn’t this “Just in Time” manufacturing?
JIT is simply receiving a shipment of inventory just as you are about to run out. It is little more than delaying your
replenishment order. Lean, in contrast, is all about moving a product or repair through the shop faster.
Where can I get more information about Lean?
Additional information about lean can be found on this site. In addition, there is a list of recommended reading
materials, which provide a good foundation for understanding lean principles, but You have to remember that
Lean is real actionable work. It’s the purest work on business process and it can give You only practical Lean
Action Work Out.
TOOLS
How Do I Define a Line or Cell?
It has to do with how equipment is arranged so people & materials interact in an efficient fashion. Process steps
need to follow the PR analysis with no material queuing between process steps. The net effect is the lead time
(cycle time) is shortened. This is why we create lines or cells. Here are the defining attributes of a line or cell:
Single Piece Flow
TAKT Time Production
Pull Production
Standard Work
Standard WIP
Why is a Model Line Important?
Since Lean is derived from the Toyota production system, our businesses need to understand how the Lean tools
apply to them. The most effective way to do this is to pick one place in a business and deploy as much of the Lean
toolkit as possible. This gives you the ability to demonstrate the use of the tools so you are no longer talking
theory. This pays off big-time when you begin translating the toolkit to other parts of your business.
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What Does Translation Mean?
Once you build a model line, you have demonstrated how the lean concepts apply to your business. We can take
those learnings and apply them to other parts of the business through translation. We are translating concept for
instance, the way that DASH designed pull may not be the exact way you do it. Your solution should be tailored
to your needs. This is how lean is designed; lean teaches the concepts. It is up to everyone in your area to work
together to convert the concept to a solution that works for you & your customers.
How Should I Setup My Supermarket?
There are 2 basic supermarket situations:
A supermarket that supports a line producing to TAKT time should arrange the items to be a mirror image of the
material presentation on the line, this includes items that go into kits.
A supermarket containing accessories or options heavily used at the end of the quarter should arrange the items to
be in alpha-numeric sequence. Because of the end of the quarter rush, we tend to have strangers picking, this
makes it easier for people to know where items are.
What do I do with the Supermarket when Components are Used on Multiple Lines?
We must always begin by fully understanding which components go into which products & on which lines/cells
(Part Geneology, Product Tree & PQ Analysis will help). The components in the supermarket should then be
divided into:
Components unique to only 1 specific product; grouped together by product
Components unique to 1 line/cell (multiple products); arranged alpha-numeric
Components used across multiple lines in a factory; arranged alpha-numeric
How do I know if I should do kitting or a 2-bin style material presentation?
There is no definitive answer to this however, we do have factors to consider. Like most of the Lean tools, TAKT
Time will be our reference point. Here’s a good rule of thumb. If the kit accumulation time is more than 25% of
the TT, you may be spending too much time making the kit, and a 2 bin system might be the best solution for you.
At What Percent on the PQ Paretto Should I Cutoff Make-To-Forecast & do Make-To-Order?
There is no definitive answer to this, but there are factors to consider. 80/20 Rule, Testing Time, Quality Issues &
Supplier Lead Times for the low runners on the PQ paretto. As you become more proficient with Heijunka you
should migrate to producing as many of the models as possible to Make-To-Forecast.
Who Performs TPM in My Shop?
TPM is performed by a professional group within your organization, not the operators. Operators are responsible
for ensuring quality standards & performing standard work.
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