Lean Six Sigma Academy

One Piece Flow versus Mass Production

February 18, 2008 By Ron Pereira 75 Comments

In this video we watch the traditional “mass production” manufacturing technique square off against the lean “one piece flow” methodology. Have a watch to see who wins!

This is my first attempt at making a video like this. I must admit, talking into a camera is much harder than pressing these keys! With this said, you can expect much kaizen to be done as I work to improve my “skills” in this area.

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Filed Under: Lean Fav, Video Tagged With: Lean, one piece flow

Value Stream Mapping Overview

February 8, 2008 By Ron Pereira 16 Comments

Update: This entire value stream mapping series of articles is now available in a professionally recorded audio book.

One of, if not the single most powerful lean tool available to us is value stream mapping (VSM). The reason it’s so powerful is because of its relevancy.

You see, it doesn’t matter if you are an accountant who sits behind a desk, or a nurse caring for the sick, or an assembler building a Toyota Camry – value stream mapping can help you see wasteful activity in a new way. I guarantee it.

There are some excellent books written on this topic and I will point to them later. But for now, I want to take my own shot at explaining this wonderful tool to you. And, yes, the price is right if I don’t say so myself.

Since this topic is so large I will be breaking this up into a series of articles. As of right now, this is how I see things going.

VSM Overview (this article)
Introduction to PQPR
Current State VSM
Future State VSM
Action Planning

So, let’s get started.

Definition of a Value Stream

A value stream can be defined as all the steps – both value added and non value added – required to take a product or service from its raw materials state into the waiting arms of a happy customer.

VSM Overview

Initially, value stream mapping can seem a bit intimidating. There are lots of funny looking icons and zig zaggy lines that upon first glance seem to do nothing but confuse things. But once you understand what you are looking at you will be hooked forever.

Like most things related to lean and six sigma there are some general steps to follow when we create value stream maps. Here is how I do it.

Step 1: Identify the Product Family

The first step I recommend you take is to identify the product family you wish to map. The tool to use for this is a PQPR (Product Quantity / Product Routing) matrix. This tool will help you identify which product or in some cases products to focus in on.

I cannot stress how important this step is. I have seen too many excited people run out and start mapping the first product or process they see. While value stream mapping anything is better than nothing you definitely want to focus your efforts on the most important areas first.

Step 2: Create a Current State Value Stream Map

Once you identify what to map you and your motley crew must set off and create a current state value stream map.

As the name implies we are interested in how things look today. We are not interested in how things “should” look or were “designed” to look. No, we want to draw reality onto a piece of paper.

The piece of paper is a key point. While I am a big advocate of using software to draw our final maps up, I cringe when I see people attempting to go straight to the computer.

A stopwatch, oversized piece of paper, pencil, and good eraser are all you need at this point.

Step 3: Create a Future State Value Stream Map

Now that we have a better understanding of the current state of affairs, which is typically one eye opening experience by the way, we are ready to draw a picture of how we would like things to look in the future.

Typically, as an example, we aim to make things flow and reduce the amount of inventory or waiting in between steps.

It’s at this point when people get to dream a little. You know, create the ideal working place.

Step 4: Create an Action Plan

Now that we know how things are working today and how we would like to see them working in the future it’s time to form a plan.

There are a variety of templates available for this. The key is not which kaizen newspaper or A3 report you use – instead it’s that you and your team know exactly what needs to happen and when it needs to happen.

In short, we form the plan… then execute the plan!

Next Up

In the next installment I will explain exactly how to complete a PQPR matrix.

To make sure you don’t miss it please subscribe to LSS Academy via our RSS feed. Alternatively, you can enter your email address in the box towards to top right hand side of the page to get this series delivered straight to your inbox.

Read the next article in this series: How to Create a Product Quantity / Product Routing Matrix

Filed Under: featuredpost, Lean, Lean Fav

OEE – Not Just for TPM Programs!

December 20, 2007 By Ron Pereira 4 Comments

If someone were to force me into a corner and only allow me to use one metric in my plant I would have to choose Overall Equipment Effectiveness (OEE). The reason I would pick it is simple… it is really 3 metrics in one! Here is a quick summary of how this powerful metric works.

The 3 Pieces of OEE

OEE looks at 3 areas:

Performance: Here we compare the actual output with what that particular piece of equipment should be producing. We are really focusing in on what we call “speed losses.” For example, due to the hardness of a particular material the lathe may need to run at a slower speed than normal. So, in a given day a machine should produce 100 widgets but at the end of the day it only produces 85 widgets so we have a performance of 85% (85/100).
Availability: Here we look at how much time is available to run the machine (taking out breaks, etc.) and how much we actually ran the machine. With availability we are primarily looking at our losses associated with downtime. Things like setup time, machine breakdowns, and startup losses are common culprits of availability losses. So, if there were 7 hours available to run the machine and we actually ran 6 hours our performance is 86% (6/7).
Quality: Lastly OEE also looks at quality. If 80 out of the 85 widgets were acceptable (5 bad) we have a quality score of 94% (80/85).

Once we have our three percentages we simply multiply them together to get our OEE. In our example, we have an OEE of 69% (85% x 86% x 94%).

Depending on which book you read or consultant you talk to you will hear various opinions of what “world class” OEE is. I work with the thought that if you have an OEE of 80% or more you are doing well. Really well actually!

Not Just for TPM Programs!

The one thing that really irritates me is how so many people think OEE is just a maintenance thing. If we go back to the aforementioned books and consultants we mostly hear about OEE in the TPM (Total Productive Maintenance) chapter or module. This is fine as OEE and TPM definitely go together. But let me just get on my soapbox for a bit. OEE is arguable to most holistic productivity metric known to mankind.

So if you think the maintenance guys are the only people that should be driving OEE with their TPM program you are dead wrong. Anyone and everyone that cares how many widgets are produced in the plant should care about OEE.

The operator should care (and be intimately involved in capturing the data). The line supervisor should care. The quality manager should care. The plant manager should definitely care. The maintenance team should care. Even the controller, who wants to see all the cash flowing on the financial statements, should care. Heck, your significant other, who wants to see you employed for a long time, should care about OEE! It’s just that important.

Here is free video and OEE calculator you can download. And yes, I know, it is in the TPM section of this website. C’est la vie.

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Filed Under: Lean, Lean Fav Tagged With: Lean, oee

Two Types of Kaizen

October 28, 2007 By Ron Pereira 10 Comments

First of all… how about them Buckeyes? We still have 3 very tough games to go against excellent teams so there is no room for too much celebration. But whipping the Nittany Lions on their field in a night game with more than 110,000 maniac/screaming fans all dressed in white makes me smile. The best thing of all is this is a rebuilding year! I love Jim Tressel. Anyhow, back onto topic.

Buzz Words

The word kaizen is fast becoming a buzz word galore. You will hear about how people are “doing kaizen” or running a big “kaizen event” next week. Many times folks are in fact executing kaizen’s in an attempt to make things better and I applaud them.In addition to the infamous “kaizen mind set” there are at least two, possibly more, types of kaizen events I am aware of: point kaizen and system kaizen. Let’s discuss them.

Point Kaizen

From my experience the most common type of kaizen practiced is called point kaizen. These kaizen events typically come about as the plant manager is walking through the shop (a great thing by the way) and notices a mess in cell 4. So he or she finds the supervisor of the cell and discusses it. The supervisor gets the hint and launches an immediate 5S kaizen event in the area. Great stuff to be sure… but we must be careful lest point kaizen consumes us and we lose focus on the entire system.

System Kaizen

System kaizen, in contrast to point kaizen, comes about when this same plant manager realizes that their flagship product line is suffering from a growing past due backlog, too much inventory, and overall poor morale from the folks adding value to the product.

With this in mind, he or she works with the team in developing both a current state value stream map and then a future state value stream map. This future state value stream map is a view of how the team wishes to see things working in a pre-determined time frame (e.g. 3 months, 6 months, etc.).

Things like tidying things up via 5S, creating model cells, and implementing WIP and finished good supermarkets may be some of the things needed in order to reach this future state.

System Kaizen leads to Point Kaizen

What the team soon realizes is that the 2 day value stream mapping “system kaizen” exercise lead to the identification of multiple “point kaizen” events. And once these point kaizen events are successfully complete the team should be much closer to their future state vision.

So, while point kaizen is never bad, I feel it extremely important to mention the need to first look at things from a “system” perspective before worrying about things on a “point” perspective.

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Filed Under: Lean, Lean Fav Tagged With: kaizen, Lean

Why Flow Counter Clockwise?

September 30, 2007 By Ron Pereira 8 Comments

When designing a u-shaped cell it is often recommened that material flow in a counter clockwise direction. Why is this?

It’s about the right hand

Research shows that most people are right handed. I have heard that as many as 85% to 90% are right handed. Why does this matter you might wonder?

Well, when you think about what happens in a cell we know that first we must pick the product up. Since we have to “aim” so to speak to pick it up we tend to want to use our dominate hand.

Further, once we have “added value” to the product we are ready to simply pass it on to the downstream process. There is not much “aiming” involved with simply placing something down.

So, with this known we can see why having things flow counter clockwise or “left hand inside” makes sense when most people are right handed. We pick up with our right hand (when we need to aim) then put it down with our left (when no aim is needed).

It’s about the horses

While the right hand dominate aspect may be the most common reason for flowing counter clockwise there is another reason that is quite amazing. Have you ever seen a horse race held where the horses ran clockwise? Probably not. In every horse race I have seen the horses run counter clockwise.

The same thing applies for track athletes and race cars. They also move around the track in a counter clockwise manner. You may not have ever given this much thought but there is actually quite a bit of “brain science” behind this. I must give credit to my friend Jon Miller for first explaining this to me. Well, he explained it to a lot of people in this post some time ago. He wrote:

One of the strongest reasons given for the innate “left hand inside” preference for human motion comes from brain science. According to a Professor Matsumoto, since the right brain processes spatial recognition human perception of space is stronger through the left side of vision (the hemispheres of the brain control opposite sides of the body).

When you are running “left hand inside” or counterclockwise, you have better visibility of space on the left side and you are able to run more comfortably, confidently, and quickly.

Here is a little test for you. If you don’t believe this brain science stuff head to the closest track and run a lap headed clockwise and time yourself. Then, take a rest and run another lap counterclockwise and time yourself. Chances are very good that your counter clockwise time will be several seconds faster than your clockwise time.

Of course you should do this a few times to make sure. In addition to learning about lean you will be doing some great exercising… which is lean as well I guess. Yeah, I know, that was a really bad joke.

My cell flows clockwise… am I evil?

So, what to do if your cell or cells flow clockwise? Does this mean you are not lean? Of course not. In fact, I recently talked to some folks who initially designed a cell to flow counter clockwise but after piloting it the operators complained and offered some reasons why they preferred to flow clockwise which the engineers took into consideration and made the changes.

So, take this article with a grain of salt and be sure to test whatever solution you implement. In the end, the folks working on the line need to be comfortable with whatever you come up with.

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Filed Under: Lean, Lean Fav Tagged With: Lean, one piece flow

Transportation Muda

August 4, 2007 By Ron Pereira 26 Comments

We spent the last few weeks in Canada visiting family. We had an awesome trip. As we were driving from Texas (yes driving with 3 kids more than 2400 miles) I had my eyes peeled for some good lean or six sigma topics.

While driving in North Dakota I noticed something big approaching. I couldn’t tell what it was initially. As I approached the large object I realized I was looking at the essence of transportation muda (waste). What was it you may ask?

An airplane wing. I am not sure where this wing was headed as we were about 60 miles from Fargo… but rest assured no value was being added to this airplane wing or the airplane it was going to be attached to.Curious where the second wing was in this “value stream” I continued to drive only to approach wing #2 in about 30 minutes.

My photographer (wife) was busy with the kids so we didn’t get a picture of it but rest assured it was just as wasteful looking. More to come on my trip and the state I absolutely fell in love with.

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Filed Under: Lean, Lean Fav Tagged With: 7 wastes, Lean

Kaizen Rules – 9 & 10

July 26, 2007 By Ron Pereira 3 Comments

This week has been about all things kaizen. I have to come clean and admit I wrote this entire series last weekend as I was preparing to take off on vacation with my family. Thanks to the greatness of WordPress I was able to delay the submission of the posts. Yeah, I know… it’s a little mass production-ish… but hey what can I say.

In any event, we are wrapping things up this evening. We have covered lots of ground and if you have just joined us please check out the following posts.

Rule 9: Seek the wisdom of ten people rather than the knowledge of one.

Lone Rangers are a thing of the past. No matter how brilliant you are, I assure you that listening to others, and I mean really listening, will accelerate your kaizen efforts ten fold.

Rule 10: Remember that opportunities for kaizen are infinite.

So far we have discussed 9 rules to kaizen. If you remember only one of them I hope it is this last one – kaizen is a mindset and never ends.

Summary

For those familiar with the book, “Gemba Kaizen” by Masaaki Imai you may notice an interesting relationship between these ten rules and the ten rules he shares. Yeah, they are the same rules but with my comments added. So, if you haven’t read this book I really recommend you pick it up and give it a good read.

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Filed Under: Lean, Lean Fav Tagged With: kaizen, Lean

Why Heijunka – Part 1

June 6, 2007 By Ron Pereira 4 Comments

B.D. asked, “You’re talking about HOW to do heijunka, but I’m not seeing WHY.”

Great comment B.D. I will attempt to answer the why here this evening. Let’s dig into the manufacturing side of things in this article and tomorrow night I will write about heijunka in the front office.

Taiichi’s Take on Heijunka

First, let’s start with some words of wisdom from a man of immense wisdom.

“The slower but consistent tortoise causes less waste and is much more desirable than the speedy hare that races ahead and then stops occasionally to doze. The Toyota Production System can be realized only when all the workers become tortoises.”

- Taiichi Ohno

Heijunka Review

Last night we introduced the basic concepts of heijunka. To recap, let’s assume a company generally sells equal amounts of two particular products – A and B.

A mass producer would likely tool up and run a giant pile of A’s, switch over and run another giant pile of B’s. These evil people, OK they are not evil just misguided, normally live by the mantra “build it and the orders will come.” Funny thing those orders… when we want them to come they rarely do. And when we are not quite ready they flood in.

In this same situation, a lean producer would likely attack this demand as follows: ABABABABABABABAB. If you are new to lean this is perhaps the most counterintuitive thing you have ever seen. I will grant you this… I really struggled with heijunka myself. But by keeping an open mind and actually seeing it work I came to believe.

So Why Heijunka?

There are many reasons for implementing heijunka. I will touch on a few that helped me understand this concept.

First, building in huge batches is not optimal for many reasons. One that impacted me greatly at my previous company (a mobile phone manufacturer) was that customers change their mind – a lot.

For example, if I thought I needed 100 red toasters, 50 blue toasters, and 25 green toasters this month based on hard orders and a forecast I may set off and build all 100 red toasters first, then all the blue, and last but not least those shiny green toasters.

This is all well and good until the worst thing that could ever happen to a mass producer happens. Let’s say we are on red toaster number 98 and our friend Sal, from sales, calls and explains, “Hey buddy, great news! I just got our customer to commit to 200 blue toasters! Isn’t this great? I mean we are making a killing on the blue toasters. Oh, yeah, and Ron (I sheepishly answer yes) they only want 25 red toasters now so can you just tweak that little MRP system of yours and make it happen? Thanks buddy. You’re the best.”

While this may be great news for Sal I am now stuck with a bunch of red toasters. Granted, we may sell them next month. But now we enter that dangerous game of “demand gambling” and the good guys rarely win this bet.

Now, had we leveled production as previously discussed we may have only produced a few red, blue, and green toasters enabling us to be much more flexible and not be stuck with all the red toasters. Truth be told, even lean producers get nailed with demand changes… but these situations are few and far between as compared to what mass producers deal with.

Additional Benefits

There are also many more advantages to heijunka.

The “bullwhip” effect is common in mass production circles. The slight twist of the wrist (i.e. demand) can create a massive strike at the end of the bull whip. This means even small demand variations can wreak havoc throughout our plant and especially with our suppliers. If you don’t believe me just ring up some of Dell’s suppliers and ask them how demand gyrations impact them. Dell doesn’t just flip their wrists… they wind up and pound on their suppliers. When we level production the entire value stream, including our suppliers, can cope much better.

Heijunka also allows us to schedule resources (equipment, employees, etc.) in a more balanced manner. Instead of having employees stand around in January or February, when demand is lower, and then watching them run around like maniacs and paying “mandatory” overtime in October and November during the peak season we can level the demand producing the same or similar amounts throughout the year. In some cases this may mean overproducing and carrying a small amount of inventory during the slow seasons as we prepare for the peak season. While not the perfect situation this is far better than the alternative.

There are many more advantages I am not discussing tonight. There are entire books written on the topic. But these are a few of the biggies that helped me get over the heijunka hump.

Challenges to Heijunka

What about the challenges to heijunka? Dr. Jeffrey Liker explains that implementing heijunka is a “self inflicted choice.” Sounds painful, eh? What Dr. Liker means is that when we implement heijunka, and one piece flow for that matter, we can no longer allow things like long changeovers to exist, or to produce defect after defect, or to basically hide behind the piles of inventory mass producers do. These crutches are gone.

But even with these challenges heijunka yields far more advantages once the system is working as a smooth machine. Tomorrow night I will discuss heijunka in the front office which is what B.D. was really asking for clarification on I think.

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Continue Reading

To read the next installment of this heijunka series please follow this link: Why Heijunka – Part 2.

Filed Under: Lean, Lean Fav Tagged With: heijunka, Lean

Is Laying People off Really Anti-Lean?

June 2, 2007 By Ron Pereira 22 Comments

Update: June 3 @ 7:33 PM CST Over the weekend, this post has had some good action (via comments and emails I have received). I am modifying the original post ever so slightly to make the “assumptions” a bit more clear. This modification comes after Mark and John have posted their comments. Although I am making some changes this does not make their excellent thoughts any less relevant.

We often hear how companies “apply lean” and subsequently lay-off hundreds, even thousands, of people. Here is another example. In this article we read:

Companywide, employment is down sharply. Telect now employs 747 people worldwide, down from about 830 a year ago and 2,300 at its peak in 2000. In the past year, it has implemented lean-manufacturing strategies at its plants in Texas, Mexico, and Poland and now can achieve the same production level with fewer people, he says.

So let me ask a hypothetical question. Let’s say you, a Lean enthusiast, are named CEO of a mid sized manufacturing company.

Let’s also assume your market has turned down and the constraint is clearly outside your plant. Further, let’s assume you need to improve cash flow, reduce inventory, improve OTD, and most importantly improve employee morale. Next, assume the company you inherited was poorly managed before you came on and is not even a decent mass producer. Lastly, let’s assume that the previous management (who the board fired) went on a massive hiring frenzy over the past few years in hopes of improving things by throwing bodies at the problem.

Now then, let’s imagine you come into this situation (as CEO) and immediately implement lean and six sigma principles. On time delivery improves, inventory turns have doubled, cash flow is improving, and morale is on the way up. All is good with one exception.

After calculating the optimal crew size for each area (leaving in the ability to meet some expected increased demand) you realize you have too many employees. In fact, your calculations show you need 250 employees (including dedicated Black Belts and Lean Masters) to run the plant and you currently have 425.

The reason you have so many employees is again due to the previous management who went on the massive hiring frenzy the past few years.

What would you do?

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Filed Under: Lean, Lean Fav Tagged With: layoffs, Lean

Tsurube System

May 29, 2007 By Ron Pereira 9 Comments

After reading some Lean text books and possibly attending a conference or two many “Lean Dreams” are crushed when the practitioner is told, “Friend, there ain’t no way we are converting that $4 million paint line into some fancy little cell. You just go do some more 5S and leave the plant layout to us engineers.”

Tsurube System

After hearing this the now baptized Lean practitioner pauses and wonders what to do next. Never fear… there are ways to deal with situations like this. One of the techniques that can be employed is to develop what is known as a tsurube system.

The Japanese phrase “tsurube houshiki” describes how a two bucket system draws water from a well. While one bucket is headed down into the well another bucket is headed back up the top.

Staying with the $4 million paint line theme let’s look at a portion of a value stream map to demonstrate how this tsurube system might look (click picture to enlarge it).

There is a finished goods supermarket located after process C which has a pre-determined amount of material (pitch) withdrawn every 30 minutes. Once this withdrawal occurs a production kanban is sent to process A. This tells A to start producing; assuming of course the FIFO lane after it had not reached its capacity. From here we begin the “two bucket” system as described in the well example.

Every 30 minutes the same numbers of parts (bucket 1) are transported from the FIFO lane after process B to the paint line at the same time parts (bucket 2) are transported from the paint line to process C. While this is not the prefered one piece flow it is far superior to traditional mass production techniques.

Not ideal, but better than alternative

To be sure, it would be optimal to not have a decoupled paint line, but sometimes we must deal with the cards dealt us. In situations like this a tsurube system may be the answer.

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Filed Under: Lean, Lean Fav Tagged With: Lean, vsm

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