Lean FavVideo

One Piece Flow versus Mass Production

By Ron Pereira Updated on November 6th, 2020

Update on Nov 6, 2020: The original version of the video is no longer available. But I did want to add a note that the reaction to this original article was one of the main reasons Gemba Academy exists today. I have left the original comments below.

Original Article Publish Date: Feb 18, 2008

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.

  1. James Considine

    February 18, 2008 - 10:59 am

    Ron, this was great. The suggestion I would make is to “time lapse” the sequences where you were assembling the envelopes, to reduce the viewers wait time. Look forward to the next one.

  2. Matt LeVeque

    February 18, 2008 - 4:23 pm

    Ron – Great video. We are just beginning to implement lean and I plan to have my team watch this video to give them the visual insight they can’t get from articles or books.



  3. Ron Pereira

    February 18, 2008 - 4:25 pm

    Thank you Matt! I am glad you enjoyed it and hope your colleagues do as well. I am already thinking about the next one… so stay tuned!

  4. Meikah Delid

    February 18, 2008 - 8:35 pm

    Hi, Ron! Interesting video. I want to take it a bit further. How about putting 2-3 people in mass production forming like a production line and 2-3 persons doing each the one-piece flow process and then see it goes? 🙂

  5. Petri Tuomela

    February 19, 2008 - 3:38 am

    Hi Ron and thanks for the video. I remember reading the ‘scene’from the book, and wondered if the one piece flow would actually win.. you answered my question. I will share this video for our staff.

    I hope to see some more video’s, these illustrate the concepts better than reading from the books. Further, sharing these to people will save time – THANKS!

    Btw, previous post (Delid) idea is pretty good. Involving more people in the examples would make this example even more powerful.

  6. Sean Clipperton

    February 19, 2008 - 9:54 am


    This was a great video and was wondering if you have in a format that we could download and show? We do a similar activity with a group of 4 or 5 people, but we can’t show the waste like you do during your presentation as it stops everyone doing their work. We would like to still do our activity, but show your video and have the group think of waste they saw and the feelings that the others that didn’t have work compared to other group that did.


  7. Ron Pereira

    February 19, 2008 - 4:45 pm

    Thanks Petri and Sean.

    Sean, I am not sure I understand your question? Would you mind clarifying it again?

  8. Lester Sutherland

    February 20, 2008 - 10:11 am

    You can see from all the comments on this blog that you have filled a need. Great Job. I really appreciate that you have allowed the video to be down-loadable, I think this is very generous. Simple fast videos like this are great, but difficult to keep short, you did very well on this one. I would not edit the stuffing sequence as suggested earlier, as some may think you are playing a trick….

  9. Ron Pereira

    February 20, 2008 - 10:18 am

    Thank you Lester.

    Honestly I was really debating putting the video out there since I am not particularly happy with it. I stumble around with my words too much, etc.

    So, I am really excited people like this as I expect to get a lot better at it over time!

    Also, I figured – like you did – people would accuse me of cheating if I did a magical fast forward so I left it as is. I thought about only folding 5 or 6 sheets. But 10 worked OK I guess.

    I am excited to make the next video. Anyone have ideas for a topic?

  10. Mark

    February 24, 2008 - 2:33 am

    I am new to this and taking my lean six-sigma foundation tomorrow.
    Do you have a view of a process that involves maintenance to roads where a large amount of inventory and people with various skills are required?
    Sorry if this is not a lean scenario.
    I really enjoyed your video; it made me laugh and captured my thoughts and imagination.

  11. Sean Clipperton

    March 4, 2008 - 8:37 am


    Sorry, took so long to answer. I was wondering if you had a format that could use without all the ads as a presentation for a group.

    We do a similar activity but the thing I like a lot about your video is that you superimposed some of the 7 wastes into the video while your doing the activity. This is one thing that the particpants of the activity themselves cannot see and even after we have completed the exercise with remakrable clarity on the results we still have some that believe batching is better.



  12. Ron Pereira

    March 4, 2008 - 8:44 am

    Hi Sean,

    If you are looking for the raw video without any of the text (wastes, etc.) showing I could burn you the raw video on a CD or something.

    If this would be helpful please contact me by clicking on the “Contact” tab above.


  13. Ian Furst

    March 5, 2008 - 12:40 pm

    Great example! — need to edit the video a little I think (lost me at the 4min mark of stuffing envelopes. In health care we face the same problem with doctors offices ‘stuffing’ patients in rooms. they are all told to arrive at the same time and then the doctor slowly works there way throught them. I’ve been trying to tell others that they are better off doing ‘one-piece’ work flow and this video is a great example. I’m going to write about it in a couple of days and link back to the video here. Thanks for the resource. Ian.,

  14. Ron Pereira

    March 5, 2008 - 2:36 pm

    Thanks Ian! I am glad you enjoyed it. I definitely have much kaizen to do on future videos to make them more exciting with less “dead time.” Stay tuned for more!

  15. Marcia Hagood

    March 8, 2008 - 1:50 pm


    I wanted to thank you for putting this video out there. I was researching a paper for my Business Strategy class on mass production and found you video very informative. I was really confused about the whole lean six sigma thing but your video cleared all that up for me, Thank You!


  16. Ron Pereira

    March 14, 2008 - 8:42 am

    You are very welcome Marcia. I am glad it helped you. Stay tuned as I have more videos to come.

  17. Kathleen

    March 21, 2008 - 8:04 am

    Re: editing it. You could have two options. One cut to the chase and a link to the option of watching it in its entirety.

    My first thought tho was, introduce a defect! That’s where lean really shines. A comparative of defect management (ensuing wasted WIP etc) would make the point clear.

  18. Ron Pereira

    March 21, 2008 - 9:25 am

    Great tips Kathleen. Thank you and I am honored by your visit. I am a fan of your excellent blog.

  19. bob

    March 22, 2008 - 12:09 am

    I will say this for you, you obviously never did much envelope stuffing in your youth. You fold very slowly, and you have your paper arranged all wrong for stuffing the envelope.

  20. Michele Williams

    March 22, 2008 - 5:55 am

    Hi Ron!

    I am way out of my league here, as I am a sew-at-home designer entrepreneur, not nearly ready for mass. That being said, I AM in the process of filling a couple of large wholesale orders, and your video was EXTREMELY enlightening!

    Since I am my only employee, I have been assuming that the fastest way for me to produce large quanities of my product was to batch the order by assembling ALL of the pants, then all of the shirts, then labelling, etc etc, and I have been feeling sort of BORED and anxious all at the same time, though sewing and design are my passions. I now believe that feeling comes from working HOURS at a time and finding myself with PILES of unfinished business because the pieces and parts are all WIP.

    Starting TODAY, I am going to begin using one piece flow and I bet I’ll enjoy my work so much more and have the satisfying feeling of having actually COMPLETED something by the end of the day! 🙂

    When my clothing line DOES grow to the point where I need production assistance, I am committed to following the lean manufacturing process, and I am so thankful to have come across your video to get that idea firmly cemented in my brain! 🙂

    The video was great! On point, easy to follow, interesting to watch the ENTIRE process, and NO, you DON’T stumble across your words…I felt as though I was watching a friend demonstate and listening to a fluid conversation. Don’t be so hard on yourself! 🙂

    Have a terrific day!


  21. Ron Pereira

    March 22, 2008 - 7:10 am

    @ bob, umm, thanks for the comment?

    @ Michele. Thank you so much for your kind words. You don’t know how much this motivates me! All the best to you with your clothing line.

  22. Eric H

    March 22, 2008 - 8:39 am

    If you’re going to kaizen the video “experience”, be sure to make a “before vs after” demo! Also, for an idea for another subject, may I humbly submit this? It lends itself quite well to the format you used in this tutorial, though I would be surprised if you have dozens of diskettes from different manufacturers lying around waiting to be destroyed.

  23. Ron Pereira

    March 22, 2008 - 8:58 am

    Thanks for the idea Eric. I will add it to my hopper of ideas for future videos. All the best.

  24. Diana

    March 22, 2008 - 2:51 pm

    I thoroughly appreciate you taking the time out to demonstrate these two kinds of approach. The pros and cons pointed out on both sides are a great insight, and has helped me with re-analysing which direction would be the most practical way to go.

    Your approach to making videos to explain concepts are very helpful- keep up the great work!

  25. Keerthi

    March 22, 2008 - 11:15 pm

    Hi Ron,

    Great contribution to Lean community & thanks again. Good to here that you are looking forward to do more.

    I felt the stuffing envelops in the first batch process was done at a pace slower than the in the pace of one piece flow. Rating compensation can produce accuracy there.

    One piece flow to succeed the tasks need to be at uniform skill level. If at least one task demand higher skill the worker has to be highly skilled. An example would be the garment assemble process where mix and match of differently skilled take place in the batched processing system. In order to make such work suitable for single piece flow the process need to be de-skilled with more automation.

  26. Ron Pereira

    March 23, 2008 - 8:18 pm

    Thanks Diana and Keerthi for the comments.

    Keerthi, I went back and watched the video to see if I could notice what you described about me being slower with the batch processing.

    I must admit, I was honestly working as consistently as I could during both methods.

    I think the main benefit I noticed (and everyone sees) is related to how much of a groove I fell in when doing the one piece flow portion.

    Working in batch mode is boring and uninspiring. However, working in a one piece flow manner is far more fulfilling and it’s much easier to get into a groove so to speak.

  27. Keerthi

    March 23, 2008 - 9:43 pm

    I too went back and sew the video again. This time I find you relatively slow in the one piece flow. So I guess it was my enthusiasm playing tricks on me.

    Now only I understood the “FEELINGS” aspect of it. I could not see that aspect in the video. Thank you again. I am trying to think a topic for your next episode…

  28. Ron Pereira

    March 23, 2008 - 11:07 pm

    Awesome Keerthi. I look forward to your ideas! Have a great week.

  29. Eric H

    March 24, 2008 - 8:27 pm

    Hi Ron;

    Seems there are skeptics about. So I, hard-headed person that I am, watched the entire video again with a spreadsheet (similar data posted to my better half’s website).

    How do we account for the ~60 second difference in the two processes? (Which I contend is the wrong comparison, more below).

    Average time to fold:
    Batch: 9 s
    Lean: 8 s

    Average time to stuff:
    Batch: 4 s
    Lean: 3 s

    Average time to seal:
    Batch: 2 s
    Lean: 1 s

    Average time to stuff:
    Batch: 1 s
    Lean: 1 s

    So, over 10 repetitions, the lean method got a total of 10+10+10=30 seconds of advantage from the shorter time to fold, stuff, and seal.

    Could the shorter fold time be due to thinner paper used the second time? Or to the fact that you seem to get better as you go (you start with times of 9-10 s, but end with times of 7-8 s). The shorter stuff and seal times, though, are due to the fact that you are already holding the item from the previous step. You gain 1 second each time from not having to find and pick it up. That’s part of the point, so I contend that it’s unfair to count those against you as if they were a parlor trick of some sort.

    Still need to account for 30 seconds, though.

    You lose between 2 and 5 seconds every time you move the pile around between steps. Also, you have to manage the pile several times during a task, something you don’t have to do nearly as much with OPF. This also has a factory corollary: storing, moving, retrieving, and looking for WIP.

    But those are the wrong numbers to compare. The real advantage, though, is the fact that you are knocking out a complete product roughly every 15 seconds with OPF. Every 15 seconds, the lean manufacturer fills another order. Every 15 seconds, he has the opportunity to inspect WIP and final product for defects.

    Heck, let’s even spot the batch production method the 3 second difference (most of which is legitimate gain) so that they both average 18 seconds. The lean producer would be still be fulfilling another order every 18 seconds. The Batch producer doesn’t get any orders filled until 3:47. What if they were hours rather than seconds? With 40 hours in a week, that means that the lean producer is shipping twice a week while the batcher is shipping every 6 weeks. Do you like the idea of cash flowing in twice a week, or every 6 weeks?

    For the sake of the skeptics, next time you do something like this, make sure you do the lean method first so that your task times improve more for the batch method. Heck, handicap yourself for the lean method; use one hand and your teeth or something. 18 seconds beats 3:47 like a rented mule.

    • Kimmo

      September 14, 2013 - 3:55 am

      What if there were four people executing the batch prosess. One for each step, doing the step whenever there is material ready. Customer would surely get the first product earier than 3:47. In fact, there wouldn’t be any significant difference for the first outcome. So 18s against 3:47 is really unfair comparison. Otherwise interesting experiment…

  30. Ron Pereira

    March 24, 2008 - 8:37 pm

    Holy smokes Batman! That is some analysis, Eric! I am going to throw this comment up in a post to make sure everyone reads it. Thanks so much for your excellent contribution.

  31. Keerthi

    March 26, 2008 - 9:49 am

    Good job Eric.

    How about making a cup of tea in a typical kitchen and a Lean kitchen?

  32. Roxanne Veronneau

    May 19, 2008 - 7:42 am

    Great video, no nonsense approach, Methodology made simple… Looking forward to more presentations.

  33. Michel LOYER

    August 27, 2008 - 9:20 am

    Great and So simple.

    Thanks for such a clear demonstration of the one piece flow. I will use it the next time I need it to convice my customer.
    Perhaps will I add :
    – a lack of Stamp to simulate the supplier default
    – a defect in putting the paper into the envelope

    Thanks again.
    Apologize for the bad English

  34. kanwar

    October 13, 2008 - 7:49 pm

    awesome work

  35. chris

    October 17, 2008 - 2:50 pm

    I can’t get the video to load, can you email it?

  36. Yatin

    November 16, 2008 - 12:50 pm


    One thing I still don’t get….how does the average time to fold, stuff and seal go down in a lean one-peice flow as compared to a batch processing? Beats me !!

  37. Ron Pereira

    November 16, 2008 - 1:44 pm

    Yatin, in essence it probably doesn’t… what is decreased is all the extra picking up, putting down, etc. That is the reason OPF beats batch in most situations… all the extra stuff in between the value added work is eliminated or reduced in a radical manner. Make sense?

  38. Yatin

    November 16, 2008 - 8:12 pm

    Still don’t get it. Where are the extra* picking,puting etc?

  39. Ron Pereira

    November 16, 2008 - 9:03 pm

    Let’s think about “touching envelopes” as the example.

    When batching I stuffed all the envelopes and then sat them down which means I had to pick an envelope up and then sit it down. Once I was ready for the next “process” (lick envelopes) I had to pick this same envelope up again. Finally, once I licked all the envelopes I had to pick that same envelope up a third time to put the stamp on.

    When doing OPF I only had the pick the envelope up once… then I stuffed it, licked it, and put the stamp on. So, instead of having to pick it up and do something to it 3 times I only had to pick it up once.

    Make sense?

  40. Yatin

    November 17, 2008 - 8:06 am

    Wow! Gotcha! That’s neat..didn’t strike me..Thanks a lot.

  41. Ron Pereira

    November 17, 2008 - 8:58 am

    Glad I could help and thanks for the great question. All the best, Yatin.

  42. Yatin

    November 17, 2008 - 9:41 am

    Am back. You really made me think. What if I throw in 3 operators as someone suggested? The picking up & sitting down of envelopes would still happen in a OPF..won’t it?

  43. Ron Pereira

    November 17, 2008 - 10:04 am

    Hi Yatin, perhaps. I’d like you to think about it and come back in 24 hours and tell me (and everyone else reading these comments) what you think. I’m sure you can come up with a good answer. Once you come back with your thoughts I will share mine as well. Have fun and happy thinking!! 🙂

  44. Ralf Lippold

    November 27, 2008 - 11:39 am


    That was terrific:-)) Best presentation so far I have seen or experienced.

    For most people this will look unreal and as long as they don’t experience it themselves they probably won’t change.

    STABILITY is the main issue -as you said- and that is definitely true to my experience.

    Keep up the great work.



  45. Ralf Lippold

    November 29, 2008 - 6:24 pm

    Hi Ron,

    We would be highly interested in the video for showing at present LTT in Leipzig today, 30th of November.

    Any possibility to do so?

    Thanks a lot and best regards


  46. kevin

    January 9, 2009 - 9:25 pm

    this is wrong
    it’s not faster there’s no simultaneous processing. the only 2 obvious reasons that i can think of why it’s faster doing it with the one piece flow method:
    1. they’re not identical in terms of positioning the envelopes, doing the actual operations of glueing, etc.
    2. learning curve. the first method allowed you to learn how to do it and by the time you did the second one you’re already better at it.

  47. Ron Pereira

    January 9, 2009 - 10:46 pm

    Thanks for the comment, kevin. Rather than disagree with you or try to convince you otherwise… I welcome you to try the experiment yourself.

    I’m extremely confident you’ll arrive at similar results. All you need is some paper and envelopes!

    Check back and let us know how it goes. All the best.

  48. kevin

    January 10, 2009 - 7:23 pm

    if you have one person doing the folding, one person doing the glueing, and so forth then yes you can benefit from one piece flow (with all the experiment conditions being the same in both methods and no learning as a result of doing the first method). but not in this case.
    please explain why one piece flow is better in your opinion because i’m trying to understand all this from the industrial engineering perspective.

  49. kevin

    January 10, 2009 - 7:38 pm

    probably to clarify what i said before:
    i know that it is beneficial in terms of inventory and other things. but when it comes to actual time to complete the whole operation, they are supposed to be the same in both cases.

  50. Matthieu Pometan

    January 15, 2009 - 3:21 am


    Very very great thought-provoking video. It was a very good introduction to “one piece flow” processes for the beginner that I am !

    Here are my 0.02 on the 3 operators line : Let’s break the process in
    Folding (f) +
    Transfer (t1) +
    Stuffing (su) +
    Transfer (t2) +
    Sealing (sl) +
    Transfer (t3) +
    Stamping (st).
    Ok, this makes 4 operators.

    Let’s assume that the processing times (f, su, sl, st) don’t change between the two methods.

    So what about our ten envelopes ?
    With a lot size of 10, we have the batch process time : 10f + t1 + 10su+ t2 + 10sl + t3 + 10st

    And as for the one piece flow process (if we assume from Eric’s datas that st<sl<su> f) ? Whereas the batch time formula doesn’t change, the one piece flow becomes f + 10t1 + su + t2 + sl + t3 + st, to be considered if the guy in charge of stuffing lives oversea, or at least, next door 🙂

    From another p.o.v. transferring 10 envelopes sounds as painful as transferring 1 which is, if we count total number of operations (and not overall time) we have
    batch : 10f + 10su + 10sl + 10st + t1 + t2 + t3
    opf : 10f + 10su + 10sl + 10st + 10t1 + 10t2 + 10t3
    Wouldn’t we be saving some energy (employees, machines, whatever) in the batch process ?

    Last question from my side, how long is the customer waiting ? If your customer is the postman, will he come to you every time you are producing an envelope, even if you are working in a one piece flow fashion ?

    Of course, WIP, defects, …, don’t stand the confrontation 🙂
    Looking forward to reading your opinion

  51. Matthieu Pometan

    January 15, 2009 - 3:26 am

    In my comment, please read, in the 5th paragraph st<sl<su<f (ie, folding is the bottleneck)

  52. Matthieu Pometan

    January 15, 2009 - 4:31 am

    Let me apologize for stammering and add some lines I just forgot to write in my first post.


    These lines :
    “So what about our ten envelopes ?
    With a lot size of 10, we have the batch process time : 10f + t1 + 10su+ t2 + 10sl + t3 + 10st

    And as for the one piece flow process (if we assume from Eric’s datas that st<sl f) ?
    Whereas the batch time formula doesn’t change, the one piece flow becomes… ”


    Should have been
    “So what about our ten envelopes ?
    With a lot size of 10, we have the overall batch process time : 10f + t1 + 10su+ t2 + 10sl + t3 + 10st
    With one piece flow, we have (if we assume from Eric’s datas that st < sl < su f) ?
    Whereas the batch time formula doesn’t change, the one piece flow becomes…”


    again sorry. Ron, if you could edit these, I would be grateful.

  53. Matthieu Pometan

    January 15, 2009 - 4:40 am

    This is definitely the last one, but not everything i’m writing goes through
    Am I so ill ?

    With one piece flow, we have (if we assume from Eric’s datas that st < sl < su f)

    should have been

    With one piece flow we have (if we assume from Eric’s datas that st < sl < su f) : 10f + t1 + su + t2 + sl + t3 + st. Hence OPF clearly outperforms batch processing on that point.

    But what if our transfer time (t1) gets bigger than folding (f) ?
    Whereas the batch time formula doesn’t change, the one piece flow becomes…”

    I’m looking for a place where to hide

  54. Arup

    March 6, 2009 - 12:31 pm

    Hi Ron, nice video despite the constraints you mention.

    Although I passionately sell the idea of one-piece flow to my clients let me play devil’s advocate here. The logical end to this process would be to get the letters to the post office and suppose (for arguments sake) the post office was 10 minutes away. Therefore, delivering 10 letters on the basis of one-piece flow would take 200 minutes. By carrying 10 letters in one trip this can be done in 20 minutes … saving 180 minutes and a lot of gasoline. That’s significantly more than the 1 minute gained in actual production. I know some folks would say we have a balancing problem but there is no way you can cut down the travel time unless you move house next door to the post office and that we all know is not a feasible solution. Alternatively, you could convince the postal department to come to your door and pick up each letter the moment it is ready!! That would be something!!


  55. Ralf Lippold

    March 6, 2009 - 1:38 pm

    Also a friend of one-piece-flow (as the ultimate solution or north star) I would prefer to do a SMED-approach.

    What travels have to take that bring you close to the postoffice or just a post box?

    Instead of doing the post deliver action as a single viewed action combine it with some other action (such as shopping, or visiting a customer or something that is regularly occurring) taking the post with you.

    That will save another great deal of the time;-))

    Best regards


    PS.: Always have a scope on the broader picture and what isn’t done today probably will lead to the ultimate solution of our problems.

  56. Mark Timmins

    April 23, 2009 - 9:35 am

    OPF will have the advantage if it reduces the amount of product handling. In the presented scenario, where there was only one person doing the work, the handling was reduced, because the OPF approach eliminated the wasteful steps of adding a folded letter to a WIP pile and then picking it up again to put in an envelop, and then adding the stuffed envelop to a WIP pile only to then pick it up again to seal it, etc.

    However, if each step of the process was performed by a different person, I don’t think this handling waste would actually be reduced; it would just be spread across 3 people. Piles of WIP would not accumulate, and lead time would be reduced, but the total effort to produce a finished part would be no less than for the 1-man batch process. Total effort might, in fact, be larger, because instead of moving a pile of WIP once, the “pile” (of 1 part) is moved for each and every part. If increased throughput is needed, might a better scenario be to have each of the 3 people doing all of the steps in parallel rather than each doing one step in series?

    Also, I’m curious how you respond to the challenge that there are no economies of scale to be had with OPF? OPF processes are readily scalable via mass parallelization, but only linearly, meaning it takes X times as much effort, time and material (i.e., cost) to produce X times as much product. Done right, batch processes can do X times as much product (at the operation in question, at least) for less than X times the cost. One possible answer to my own question is that there is an often significant investment of time and effort required to develop (and validate) a scaled up batch process.

    Finally, the shorter time until the first product is produced is only an advantage if you can release the product as soon as it is produced. If you need to wait until all product is made to release the batch, then this offers no advantage.

  57. boomboom

    May 12, 2009 - 10:23 am

    (edited for language)

    YOU ARE THE ****!

  58. Katie

    July 8, 2009 - 12:39 pm

    Thank you very much for posting this video. When I first watched it, I was incredulous. I said he’s not doing it right, simulating the sealing and stamping is easier/faster than doing the actual job. I say this with confidence as a person who has to do the exact fold/stuff/seal/stamp routine on 350 pieces a month for my job. So today, I decided to recreate your experiment and timed myself doing 10 pieces in batch operations (the way I normally do this task) and 10 pieces using one piece flow. The result: batching took 4:42, OPF took 3:48.

  59. John Townsend

    July 27, 2009 - 6:56 pm

    It’s pretty obvious where the saving comes in – if you have steady process, you can cut the time between handoffs. The time saved between operations is plain to see. The most important lesson it taught me is that “problems can’t hide”. If the process or operator had a problem in the lean method, it would be found straight away and fixed. With mass production, you might need to go back and re-fold everything (say, to get the address in the window if there was one). Great stuff!

  60. Chandrasiri Perera

    March 14, 2010 - 5:29 am

    Hi ,I am intersted in comments in apparel and other factory on one piece flow and mass production .
    Also please send me email about your comments on “Unit Production System”

  61. Mikkel Smith

    February 14, 2011 - 6:48 am

    Great video – thanks!

    When I work as a consultant I try to make my customers think in one-piece flow. But I have to admit that I sometimes also try to sell them “batch production” – but just in smaller batches than they work with today.

    The reason is that it sometimes leads to more waste to run one-piece flow. Like in an office or a production where a process it too short to justify a transportation for each product. Then I rather talk about frequency of transportation between processes. Where they today hand over products (papers or parts) e.g. every 2nd day (could be much longer!) they now change to e.g. 2 times per day.

    I use a self-made example to illustrate one-piece flow at courses etc.
    Round 1: 10 workstations. All products = LEGO bricks at workstation 1. Now the operator should assemble 10 “products” running back and forth with parts doing assembly.
    Round 2: The LEGO bricks are now placed a 5 workstations with one-piece flow.
    Round 2 is 30% faster than round 1.
    Approx the same result as you get.

    I would like to make a video with my example and share it with you once it is ready.

  62. Andrew Mountjoy

    February 28, 2011 - 5:39 am

    I was just thinking.. So say I want a solar panel on my roof, is the one-piece processing better for that? I’d place the order with a fitting company, they would then order it from a supplier. The supplier would then build then construct the solar panel, build it, test it and deliver it. Id’ then have it fitted.

    Using mass production, would the item be in stock and already tested? Wouldn’t the customer see the item in days rather than the entire time it would take to produce the whole thing from scatch?

    In the example you showed, it relies on the fact that a single operator is present. What if for each envelope you folded, you had to wait for the tree to be cut down for the paper by a single person? Batch processing a tree for all the paper is surelt more efficient in this case?

  63. William

    April 3, 2011 - 2:46 pm

    This is very informative, thanks! But as someone who has had to do this exact process of sending out brochures, I have come across a number of issues with OPF.

    Your example has 4 steps and it is relatively easy to remember to do all steps. In my situation, I have had anywhere from 6-10 steps (multiple pages to be folded, return label, “please post” stamp) and it gets much more difficult to remember each step. You waste a lot of time going back to check that all 10 steps were completed for each piece.

    Additionally, it a lot of cases, you need to match up a specific piece of paper with a specific envelope. For example, an uniquely addressed letter must go in the correct uniquely addressed envelope. If you find a mistake during OPF, you must go back and re-open many envelopes to find the incorrect one, wasting huge amounts of time, not to mention creating a lot of stress.

  64. Nady San

    August 12, 2011 - 10:05 pm

    I like this process and I think this is a very clear way of presenting the Lean methodology …

  65. Jophine Pranjal

    September 3, 2013 - 9:18 pm

    Hi Ron,
    It was a great video. You proved one piece flow has higher efficiency than mass production. I like this not because, it is one minute faster than the other, as shown in your video (it does lack some experimental error because, I feel that you were able to do the experiment faster in one piece flow due to the experience you gained initially in mass production) but, the like part is that the customer need not wait for a very long time to get the first piece and the system is under control also less room fro chaos.

  66. Suresh

    January 31, 2015 - 3:40 am

    Excellent Video to explain the mall batch size. It would have been time saving if it was time lapsed. Thanks for the content.

  67. Fredrik Vestin

    January 1, 2021 - 10:52 am

    Ron, thanks for the video. However, the statement that “one piece flow is always going to be superior” is only true if you assume that the setup cost for each step is zero. Only if that is true you can assume this, right?

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