I first heard about “lean” in the manufacturing context maybe 15 years ago – a new manager showed up at a place I was working and somebody said (quite dismissively) that he was into “lean six sigma” as if that was supposed to mean something. It didn’t. I left that job a few months later and nothing had changed much, except that we made a big deal about moving supplies to carts near each work area. It didn’t surface for me again until I was running my own shop and had come to the realization that we weren’t making things easy for ourselves. I didn’t know what to do exactly, but I knew that things that should be easy were hard, and that people were frustrated and we kept dropping the ball on simple stuff. People were always coming to me to ask what to do, and I could never find any tools when I needed them. Somehow this felt normal – and even ok. I figured… work is hard sometimes.
This article is meant as a 15 minute overview of lean and some core concepts. There are links to books and resources at the bottom of this page. If you’re interested, I encourage you to dig deeper. It’s kind of hard to get your head around at first – or at least it was for me. Total game-changer though – really.
Cracking the Nut
The first step in my learning happened when I was given a book called “Joy Inc.” It is about a company where they practice a type of work structure (similar to Scrum, I later learned) where teams work in an open reconfigurable work space and focus on taking steps toward small immediate goals in an iterative process – with lots of customer feedback. They plan work in small (weekly maybe) increments and then visually show its level of completion with note cards, string and sticky dots – like on the wall! Each day they have “stand-up” meetings so people can share where they are with a project and what they need to get it done. They have a flat management structure, little overtime and flexible hours. The idea is that people are more connected, productive, and happy in their work and they avoid long running misunderstandings and management struggles. Apparently it works. I had never even imagined that the problems we had were solvable – or that there were whole disciplines devoted to the study of people at work. So I started to read more books…
A little later somebody lent me a copy of “The Goal.” I loved reading about the struggles of plant manager Alex Rogo and seeing our own problems through the lens of throughput, inventory and operational expense. A big lesson for me was about dependent events (like a project with hundreds of individual steps) and “statistical fluctuations” and how when something slows down one step it has an impact across the whole project that you can’t catch up from. And then the bottlenecks – the idea that downtime on a factory’s bottleneck operations is equivalent to downtime on the whole factory! And batch sizes – reducing batch sizes!
Then I heard about Paul Akers and got his 2 Second Lean book – and then there was no going back!
I didn’t know it but these books and many of the others are based on the foundation of “Lean” which itself grew out of Toyota’s production system developed in Japan in the decades after World War 2. Toyota manager Taiichi Ohno developed a system to build cars that was itself based on Henry Ford’s system and the work of Frederick Taylor – but more flexible and with a focus on flexibility and reduced inventory – because they couldn’t afford inventory! This discipline migrated out of Japan in the 1980s and became known as “just-in-time” manufacturing, “kaizen”, and “lean manufacturing.” It is the basis for what we now think of as “Lean.”
Ten Wastes
A major part of lean is a focus on “waste” – combined with a broadened definition of what can be considered waste. Taiichi Ohno proposed seven types of waste and and authors Geoffrey Mika, James Womack and others agreed on three more in the 1990’s. When I first looked at this list I began to see myself, our team and some of the many things we were doing each day – and I started to feel like a moron! Here are the categories of waste:
- Transport: Moving things around in ways that are not directly related to production.
- Inventory: All the stuff – stock, work in progress, things not actively being worked on, finished goods, etc.
- Motion: People and stuff moving in ways that aren’t directly contributing to production.
- Waiting: You know – waiting!
- Over Production: Producing beyond the needs of current demand – producing for stock. Producing because “productivity” feels good.
- Over Processing: Doing things the hard way – not making it easy to do each step, wrong tools, crappy setup, etc.
- Defects: Rework, fixing things that shouldn’t need fixing.
- Wrong Metrics: Not knowing what good is, eyeballing it, not being able to measure good from bad, in spec… or out of spec.
- Human Skills: Not using the whole capability of a person, their ideas, potential input, clever solutions to problems.
- Computer Misuse: Not kidding – time wasted making mistakes with or messing around on the computer – Craigslist, Ebay, HGR Surplus, I’m lookin’ at you!
So that is a pretty broad way of looking at waste… At first it seems kind of tyrannical – like next thing you know the boss will be out measuring you with a stopwatch. And this is where people misunderstand lean and it goes off the rails. From outside it looks like just one new “initiative” where management tries to squeeze more out of the same people while making them easier to replace with cheaper people. A fair concern! But who actually wants to do something the hard way? Do you like picking things up and putting them down for no reason? Do you like fixing something you messed up in the first place – because you didn’t have the tools or information to do it right? Do you like it when your boss tells you to just shut up and do what she says? How about waiting – can we hear it for waiting?
Nobody wants to do any of this stuff (except maybe #10 – no I LOVE doing that one!) and that’s whats great about lean – it’s really just about making it easy for people to be awesome. People think that because it is good for a company, it must be some kind of raw deal for the employees – and done wrong it totally can be. But when management sees lean as a way to make it easy for everybody to have better and more satisfying jobs AND produce better, more profitable products – that a win!
Continuous Improvement
You can’t get rid of all the waste in one day. You probably can’t get rid of ALL the waste ever – but you can creep up on it. Central to lean thinking is the idea of “kaizen” – that is, continuous improvement – like over and over – forever. When you improve even a small thing, you get to keep that improvement into the future. When you improve things a small amount every day, week, month, year… pretty soon the changes are huge! Continuous improvement is the compound interest of gettin’ shit done.
So lean becomes more of a philosophy than a process to be followed. People who were wary of this “8 wastes”, “continuous improvement” and “5S” nonsense will see their work getting easier. They don’t feel so concerned about sharing their institutional knowledge because they feel like part of a team. Management has to be fully supportive of bottom-up improvement – you can’t send a team of engineers down to the floor to tell the line-folks how to improve their work process – it has to come from the worker’s own experience. Of course the engineers can weigh in – but lean breaks down if you make it a top-down directive, rather than a team process. And you have to promise not to fire people when the whole team gets more efficient – that is important! Then you need to keep that promise.
Some things can’t be iterated easily. It is relatively easy to make changes to the g-code for a CNC trimming operation. Modifying a gel-coated production tool is more of a commitment. Not everything can be tweaked at will. Composites have their own challenges and you may find that experimenting is scary because the downside of a scrapped part is expensive. You may get more mileage out of changing the way people work on things and how you structure the flow of work, rather than trying to sell engineering on a material change or take a tool off-line for a week to re-work filtering. Low-hanging fruit may keep you busy for while! The more you look, the more fruit you find.
Inventory Reduction
Another key “result” of a lean philosophy is the focus on minimizing inventory. I first encountered the term “WIP” (work in progress) directed to a huge pile of semi-finished stuff that had been sitting around for a few weeks because the customer didn’t need it for a while and nobody had found it urgent to do the final few steps to complete the job. It represented a sizable amount of money there and the materials had been bought, the labor paid and we had a few weeks left to get them ready to ship. The stuff was all covered with dust and was taking up a car-sized spot in the middle of the floor. I didn’t pause once to think of the cash-flow or operational implications of that pile. When I started learning about lean, I was taken aback by the disparaging way inventory was discussed. What’s so bad about having some stuff around? Come on!
The idea that inventory is money hadn’t occurred to me. Those parts in the big heap were worth hundreds of dollars each – and there were tons of them! I just knew we’d get paid for them sooner or later and it would be fine. Sure they were in the way but – whatever. The fact was we had taken people off other work to build all those parts in one big batch – it was way faster to do that right? And we’d used up a couple of grand worth of resin and fiber and a couple of weeks of labor. But those guys were on a roll – we crushed those parts! The idea that we had done a silly thing from a cash perspective only dawned on me later. We had tied up lots of money in something that wasn’t needed yet – and had neglected other more urgent work to do it. Customers were waiting for us to finish jobs that we weren’t done with while we were waiting for a customer to be ready to pay for one we had already done. Worse, we didn’t have any incentive to actually finish and pack the big batch so they were probably going to require extra work to clean and we’d probably have to do some patch work too.
This is a bummer with composites work, where resin comes in huge drums and fiber on big rolls. You always have stuff to store and end up with inventory by virtue of the way stuff is supplied. Suppliers also give pricing by volume, so you have the incentive to buy a ton of something for a slightly lower per-unit price. It is worth talking with suppliers and customers to try to reduce the size of batches if that looks like it will help. Sometimes it isn’t worth it, and you just have to deal with batching – and this is ok – but be aware of the downsides.
One Piece Flow
There’s a principle in lean called “pull” – which describes how things are timed through production. Pull is the process by which orders for a job come from the actual customer and are fed “backwards” through the production system. For example: a customer orders a red wheelbarrow. Shipping asks the packaging department for a red wheelbarrow, the packaging department asks final assembly for a red wheelbarrow, final assembly asks the paint department for a red pan and the wheel team for a wheel assembly and the handle team for two handles. Paint asks the forming department for a finished metal pan, the forming department asks cutting for a new blank and the cutting department puts in an order for one more unit of steel sheet. Meanwhile, “wheels” has built a wheel having asked the hub team and the tire team to each send along one unit. “Handles” has ordered more wood and bolts because their stock level reached a minimum threshold. Nobody actually makes anything without an order from downstream (look into the “kanban” system for managing this process.) So the wheelbarrow isn’t really made until it is ordered by the customer! The customer may have even paid for it already.
It sounds crazy and like it would never work, but that process with the wheelbarrow is called “one piece flow.” The factory (or the “line”) only builds things when they are needed instead of in big batches – with their attendant inventory between steps. Key to this is the ability to do more flexible work than a tradition assembly line and to “change gears” quickly and easily. It doesn’t sound too hard to ask the same production team making wheelbarrows to also throw in the occasional hand-truck too. They’ll need a good system for actually making these “pull” requests and to add some resiliency to the line, perhaps a small quantity of inventory (buffer stock) will be needed in a few places. Overall the goal is global efficiency of the whole business, rather than efficiency of each step in isolation. If the guy at “handles”doesn’t have a request for a handle, he can just hang out – or maybe do a little continuous improvement! It would be a waste to make handles just to keep busy because then the company would end up owning his output (and ordering more material) until a customer came along to buy it. The incentives re-align so that it makes sense to train the “handles” crew to also do other jobs – flexibility and cross-training become more valuable.
Balancing the work volumes between steps in the process (look up “Heijunka”) becomes more of a priority so the overall process completes each step in a similar amount of time. Back to the wheelbarrow example – if the “handles” team takes longer to finish their work than any other step, the process of drilling the holes in the handles could be off-loaded onto the final assembly team – bringing the times to complete each step closer.
In a composites situation, tooling often forces a kind of one-piece flow – you can only mold parts one at a time. There is an intuitive feeling that it is faster to mold a bunch, then trim a bunch and then do any other work to them in bigger batches. Don’t assume this is right. The lesson here is that one piece flow can solve lots of problems but it isn’t always perfect. Adjusting batch sizes to be smaller can help too – and allow you to make it easier for people to organize their work-flow without lots of waiting around or doing busy-work. One of the key benefits to one piece flow (or “fewer piece flow”) is that if a mistake happens – say the gelcoat sprayer is messed up or the trimming tool cutter slipped in is cutting too deep – the problem is caught by the next step before too much damage is done. Trimming a huge stack of parts wrong really sucks!
Tools
There are a bunch of process “tools” that people use to think about lean improvement. Tools make it easier to work through a process and can make big problems easier to break down. Here are some of the big ones:
Value Stream Mapping
“Value stream mapping” is a process where you look at what you do and see what activities are adding what value and how they are structured. Some of what you do each day is directed to “creating value for your customer” – and obviously some isn’t! With value stream mapping you actually draw a map of the way materials and information flow through your operation. This forces you to think structurally instead of intuitively about what you actually do at each step – and it helps you see how steps could be simplified, combined or eliminated. This is genuine operations-nerd stuff right down to the symbols and methods used to map. It’s pretty cool!
5S (or 3S)
Groups of words are supposed to be easier to remember if they all start with the same letter – but 3 or 5 – I always struggle to remember the ones that come after “sort.” I tend to get hung up on the “sort” part!
The original 5 S’s are in Japanese but there are English ones too – here they are:
- Sort – “Is everything that’s here necessary?”, “Can we move this along?”, “This here is trash – let’s take this to the dumpster.”
- Set in Order – “We should put the right tools near where we need them.”, “Lets organize and label our supplies.”
- Shine – “Lets sweep the floor after each shift.”, “If we wipe down the machines daily we’ll notice leaks quickly so we can fix them”
- Standardize – “Here’s a checklist for our weekly maintenance jobs”, “Can you print poster-size assembly views?”
- Sustain – “We’re going to keep up this 5S stuff – things are working great!”, “Will you train the new employee on our 5S process?”
Because I have trouble with complicated things so I like to think about just 3 S’s:
- Sweep
- Sort
- Standardize
“Sweep” is about getting rid of crap that’s in the way or not necessary and actually cleaning up the work area. I’m bad at this because I love marginally-useful junk and I tend to the sloppy. It’s important though, especially with teams of people because nobody knows who is responsible for what and it’s easy for junk to pile up while everybody assumes somebody else needs it. Cleaning is a team sport – don’t just throw the new guy on broom duty! You need the people who actually have the authority to move stuff along to be directly involved – like actually driving the forklift or throwing stuff in the recycling dumpster. Everybody feels better about throwing stuff out of the boss is there actually encouraging it. This step should eliminate those dusty corners in composite shops where scraps of core and mold flanges from something you haven’t build in 5 years hang out covered with sanding dust and chopped glass – you know the kind I mean!
“Sort” is about organizing yourself. Once you’ve got most of the junk out from under foot, you’ll be able to actually find your stuff and put like with like and put the things you need where you need them. This is where “continuous improvement” comes in – you will literally be sorting forever – so get used to it! There is a loop between “Sort” and “Standardize” that keeps going around and around, with a continuous hum of “Sweeping” going on all the time.
“Standardize” is the big payoff “S” – the one where you start to see real gains instead of just spending time. Here you get to actually make homes for everything and refine systems to make them easier. You found and organized your stuff while “Sorting” so now you can look critically at each station, process or operation you do and decide (for now!) how to best organize your resources and information. The “continuous improvement” loop will keep you going back over your processes, looking for things that make you cranky and making changes to eliminate the drag.
5 Whys
This is one of my favorites and its super simple to describe. There’s lots of power in peeling away assumptions by looking deeper into a problem. With “5-Whys” you just ask “why?” 5 times – when you get the answer, you ask it again! So, as an example:
“There is a void in the outside corner of this tapered tubular molded pre-preg part.” So I might ask, why(#1) is there a void in that corner? Well, there was a bridge in the vacuum bag and so it didn’t push into the corner. Well, why(#2) was there a bridge in the bag? Ummm, because there wasn’t a pleat in the corner. Why(#3) no pleat? Because the tube bag was too small for there to be enough extra. Why(#4) was the too-small bag used? I think because we’re out of the 18″ and used 12″ – technically 12″ is big enough, but it doesn’t leave much for pleats. Why(#5) were we out of 18″ bag? Well, we weren’t – the shipping and receiving guy was out sick last Thursday so the new 18″ wasn’t taken out of the tube and re-stocked until this morning.
So we went from a void in a part to a problem with the materials team. You would never make the connection from the apparent problem to the underlying issue without digging down in a disciplined way. Often you find problems nobody even considered. My example is contrived and it feels wrong somehow to jump to all those conclusions – but if you try it a few times with any problem, you may find it’s like X-ray vision for screw-ups.
Visual Management
“Visual Management” is what it sounds like – showing people what’s going on visually and in a way that is easy to understand. If lean is about making things easier, then visual management is about making complicated things obvious. I could give you directions to my house verbally but it would be easier (and you’d be more likely to remember) if I showed you a map. If your factory is making 100 different products and you need to show how to assemble each one, it will go way better if there is a big poster board with the steps for each assembly printed out at each work station rather than buried in a binder somewhere – or worse, in somebody’s head! And if you have a CNC machine cutting parts in a big noisy factory, it helps to have a little light on top that says green (all is well), yellow (attention needed) or red (oh no!) – you can gaze out over the sea of activity and if all you see are green lights you know things are cool.
There are so many kinds of visual aids and systems to make information more clear that I won’t go into it anymore here. Get your sticky-notes, shadow boards, colored paints, whiteboards and Kaizen Foam and go to town. The idea is: make it obvious. Make it easy! Don’t make people remember stuff or guess.
SMED
S.M.E.D. stands for “single-minute exchange of dies” – which is a mouthful. In the generic sense just means that changing from one operation to another needs to be fast and easy! In car factories, changing from stamping one part to another on a production line can be a huge task with all kinds of manual setup and dialing-in. If it is hard and slow to change setups, then the incentive is there to do big-time over production and build up an inventory of parts when you are set up to make them. The idea behind SMED is that if you make it super fast (just a “single digit” number of minutes) then you can change any time you want without a huge productivity cost. This applies to all kinds of manufacturing situations. From CAD templates and machining fixture plates to resin machines and press molding tools – there are lots of places where excellent systems can help reduce the cost of switching gears. Your production can be more flexible and produce only what is needed. People won’t have to do tedious and frustrating setups all the time – and you won’t waste material proving them out by trial and error.
Poka-yoke / Mistake-proofing
Have you ever seen one of those machines that has two “start” buttons far apart so the operator’s hands HAVE to be out of the way? This is called “mistake-proofing”, “fool-proofing” or if you’re reading lean literature, “poka-yoke.” It’s a system that forces a desired behavior, while mitigating the downsides of a mistake.
Say you are assembling something relatively complicated – a 20 minute job – and have have to use 35 identical small screws. You first put exactly 35 small screws in a cup – or better yet a board with 35 screw-sized holes. When you are done assembling, there should be no screws left. If there are screws left – then you screwed up! No big deal, have a look and find the ones you missed. Without separating out the “put 35 screws in a cup” step (which feels nerdy and unnecessary – right?) you’d never really know if you remembered those three screws inside the back cover – would you? It’s best to set up a process that doesn’t require perfect attention and focus (because who has those for 3 hours straight?) to get perfect results! Make your process like bowling with the bumpers up – you can’t NOT hit the target!
How to Screw Up Lean
Just the fact that lean is different is often enough to make people not want anything to do with it. Change is hard – and change that requires you to look at how you – yourself – are behaving sub-optimally (to put it mildly) – that’s never easy! The problem with lean is that it has to be seen as a process of cultural evolution, rather than a system for squeezing more profitability out of the same resources. If you do it right and people buy-in, the profitability will come as a result of being better performers all around – not by pushing the working people harder. To be successful, lean needs to be implemented from the bottom up but with the full support of the leadership. It should take a while to get the ball rolling. People need to see it as helping themselves have a better time by upping their game.
One of the major problems that often comes with a “lean transformation” is a focus on doing the activities and using the tools without thinking as much about the people part of it. It is important for the overall feeling around the change to be right. If you get all “motion study”, “5S” and “just-in-time” around people without them feeling comfortable with why – they’re going to get concerned and it won’t work. You also need to be able to show your progress in a way that makes people feel like they’re winning.
If you’re the big boss, you have to be a relentless champion of the process and sell it all the time as helping your team get even more awesome. Don’t let on that you are more interested in profit than people – the people ARE your most important tool to earn profit. Help them and they’ll help you. If they get mad and leave – especially the experienced ones who make a change like this work – you’re screwed.
What if you don’t work in a factory?
Just because you’re not part of a production line – that’s no reason to assume that these principles won’t help you out. Lean is a mindset that happens to come with a cool set of tools. I have always been involved in what you might call “artisanal” or at best “job-shop” type work. I didn’t really have to think about one piece flow – there was usually only one piece anyway! Even so, this had little impact on the benefits of lean thinking – I was just going to use a different subset of the tools – the fundamental mindset didn’t need to change. After all – there was plenty of waste going on and just the first of the five S’s was a daunting prospect!
There are lots of similar systems in use in a huge variety of disciplines. Software development and project management have “Agile” and “Scrum” – manufacturing has “Lean.” Do some research and check out the way different industries use what are basically the same underlying principles to up their game.
Culture
I am not an organized guy by nature – in fact I’m quite the opposite! Even so, when I have my act together and my stuff organized it makes me happy. It’s like a weight is lifted off my shoulders and things just flow without spikes of frustration throwing me off all the time. Most people are like this. As an individual, becoming more intentional about setting yourself up for success is very satisfying – but can a group really behave this way? Can your team at work really actually work together to get more done in less time and without getting all cranky with each-other? Culture is about habits – group habits of cooperation, interaction, competition, and the tension between individual and operational values. Culture is everything to a team, but it’s almost impossible to change abruptly. It has to evolve and be “steered” to grow in a way that benefits everybody involved – this is what “leadership” is. Lean is a methodology for steering culture. It isn’t an overnight solution. It is a way of thinking about incremental changes in habits that when they are stacked up over time can amount to major changes.
Other Frameworks
There are other “frameworks” that apply to manufacturing in similar ways to lean. The two most relevant are probably the “Theory of Constraints” (TOC) and “Six Sigma.” You will see these all kind of mixed together in the literature around manufacturing process improvement, and each is somewhat complimentary.
Theory of Constraints is based on the work of Eliyahu Goldratt and is presented in his book “The Goal” and its sequels. The theme of TOC is a focus on “bottlenecks” in a process are managed and made a priority. In a steam of sequential and dependent steps in a process (like a part moving through a factory) the slowest process will set the overall pace and inventory will pile up in front of it and mess stuff up. TOC emphasizes only considering the whole efficiency of the system, and avoiding “local optima” where measurement and management focus on isolated steps in a process – to the detriment of overall productivity. You’ve got to read “The Goal” – like now.
Six Sigma is a process developed at Motorola to manage and measure the variability and defect rate in a production process. If lean is about flow and inventory management, Six Sigma is about statistical analysis and reduction in variability and defects. The name “Six Sigma” comes from a target rate of defects of 6 standard deviations from the mean – or 6 sigma. The somewhat daunting target if 3.4 screw-ups per million tries is thrown around but the overall goal is to use a process to reduce variability. A process called “DMAIC” which stands for “Define, Measure, Analyze, Improve, Control” is at the heart of six sigma – that and lots of data. It’s more nerd stuff than lean and something that you should really only get into once you’re on a roll with less intense forms of continuous improvement. But you can earn a Six Sigma “Black Belt” – which is probably the closest most of us will get to being a real ninja.
Conclusions
Lean wasn’t appealing to me because I wanted to get better at work – it was appealing because I wanted to be less frustrated all the time! It was a glimpse of a process that could help make the hard things easier. I recognized the benefits long before I ever managed to actually feel them – and just the knowledge that other people had designed a framework that could actually work gave me confidence that it could work for me too. I’m am not an experienced lean practitioner by any means, but having my eyes opened to the way people and teams actually work, and how relatively easy it is to make big progress if you go slowly has been a big learning experience. It’s also concerning to see more clearly just how much assuming I do, and how hard it is to see the forest for all those trees!
My advice is to start small, and with your own behavior. Don’t start with a company-wide initiative or go lobby your boss to let you lead a lean transformation – embrace the incremental essence of the process. Do a little thing – then another. Start by just fixing something that pisses you off! Maybe, as Paul Akers suggests in his book “2 Second Lean” – start with the bathroom. If you’re like me, the joy you get from seeing little wins will be addictive – and your enthusiasm and approach will slowly influence others. Getting people interested will be easier if they see it as something they benefit from. It’s about seeing the little wins standing on the shoulders of other little wins – compound interest for getting things done!
If you’re where I was – having never heard of “lean” or only seen half-hearted or unsuccessful attempts to implement the process, I hope this article gave you some basic information and an introduction to what lean can be. There are so many great resources out there to help you learn more but (like so many things) the best learning really starts when you put the books down and start trying things yourself. Good luck – and have fun out there!
Resources
Here are some great resources to check out to help you learn more:
Videos
Mike Rother: The Challenge of Developing Lean Management – Mike Rother’s whole Youtube channel is excellent.
MIT Open Courseware: Ses. 1-2: The Start of Your Lean Journey – See additional videos in this series on Lean and Six Sigma
Marris Consulting: Theory of Constraints Crash Course – The whole Marris Consulting channel is a goldmine of TOC learning.
FastCap: Lean Manufacturing – Lean Factory Tour – FastCap was started by Paul Akers of “2-Second Lean” fame – their Youtube channel is excellent.
Books
2 Second Lean, by Paul Akers – Great introduction to practical Lean – it may hit you up-side the head like it did for me!
The Machine That Changed the World, by Daniel Roos, James Womack and Daniel Jones – Based on work at MIT on the future of car manufacturing – this is the original intro to lean manufacturing and its Japanese roots.
The Goal, by Eliyahu Goldratt – Instruction in novel-form. Fun introduction to TOC and thinking about systemic misunderstandings. There are two sequels the The Goal – also worth checking out.
Learning To See, by Mike Rother and John Shook – Handbook for value stream mapping.
The Gold Mine, by Freddy Ballé and Michael Ballé – Novel about the Lean transformation of a struggling business. Similar format to “The Goal” but lean focused.
The Lean Manager, by Michael Ballé and Freddy Ballé – Sequel to “The Gold Mine” – about sustaining Lean culture.
Epiphanized: A Novel on Unifying Theory of Constraints, Lean, and Six Sigma, by Bruce Nelson, Robert F. Sproull – A good view of how these processes tie together – with an excellent appendix on TOC tools and methods.
Relentless Improvement : True Stories of Lean Transformations, by Bill Trudell – Lean + boatbuilding – a chatty but excellent overview of what lean transformations look like when they work and don’t work.
Toyota Kata, by Mike Rother – Not just what Toyota does to be successful, but how they do it. Worth it!
Change Log:
Updated: 12/5/19 – Edits and corrections. SMED section.
Updated 3/25/22 – Edits, many more resources, addition of TOC and Six Sigma summaries