[HN Gopher] Limiting Work in Progress (2020) ___________________________________________________________________ Limiting Work in Progress (2020) Author : xo5vik Score : 50 points Date : 2021-04-10 08:24 UTC (14 hours ago) (HTM) web link (truemped.github.io) (TXT) w3m dump (truemped.github.io) | mikesabbagh wrote: | I think what is important is the gratification when a team | delivers a feature. If a team can produce x amount of work, if | this is divided over large number of WIP, the team will deliver | much less features and will be less happy and satisfied. but if | the team work on a smaller number of features, the team will | complete and deliver more features and be happier and more | excited to work more | kqr wrote: | Sure, gratification is important, but what really drives both | gratification and everything else is feedback. | | When you have less simultaneous work you get done faster, which | means you make decisions based on less old information. | | Imagine trying to... I don't know, play soccer where your body | movements have a five-second delay. It'll feel awful because by | the time you decide to move your body you know it's going to be | too late for any detailed knowledge so you'll have to make do | with some very primitive heuristics like "flail in the | direction of the ball and hope to get lucky". | | That's what too much WIP is. Limiting it is starting to move | and react in real time to changes. | mjfisher wrote: | If anyone wants a much more in-depth look at the concepts behind | this, I can't recommend "The Goal" by Eliyahu M. Goldratt enough. | It's a bit like The Phoenix Project, in that it's a novel about | improving flow in delivery processes, but it's much, _much_ | better, and goes into way more practical depth. You 'll learn | about not just WIP, but floating bottlenecks, buffers, batch | sizes, etc. that turn out to be universally useful concepts. The | audiobook is especially good - easily the most practically | applicable book in the field I've come across. Go read it/listen | to it. | truemped wrote: | Author here. I loved "The Goal" even more than the Unicorn | Project. Use the Theory of Constraints to identify your | bottleneck and then limit WIP at the bottleneck or elevate it. | By hiring, optimizing... | | You are right though: go read The Goal everyone! | occz wrote: | The Goal was actually the primary inspiration for The Phoenix | Project, iirc. I think it was mentioned at the end of the book. | truemped wrote: | Indeed. Both, The Phoenix Project and The Unicorn Project are | heavily inspired by The Goal. | planet-and-halo wrote: | Less known but even more applicable to software is "Principles | of Product Development Flow." I learned about that book from | the talk "Architecture Without an End State" and it's one of | the most thoughtful things I've read on the topic. It | references "The Goal" but builds out its ideas even more, | mixing in a bunch of queue theory and taking lessons from many | other areas such as statistical economics. | mjfisher wrote: | Perfect, thank you - just ordered it. | kqr wrote: | Reinertsen's Principles is an amazing book. The way he | combines lean, network engineering and all the rest to create | an actually meaningful and coherent picture of product | development is genius. | choeger wrote: | You should ask yourself where the WIP comes from. Are there | people in your org (job description ending with "nager") that get | paid for creating new tasks? | quickthrower2 wrote: | Be suspicious of any activity added to workload that hasn't | been scrutinised. A pet peeve of a nager isn't necessarily the | most valuable thing to work on. Neither is necessarily the work | that makes the salespersons job a bit easier to sell the | product. | osmarks wrote: | It seems like the model in this is assuming the conclusion of the | post. | TeeMassive wrote: | I never truly realized that doing things in parallel was WIP | itself, even if I have read the Phoenix Project. I mean now it | just makes sense and I kinda feel dumb. | Animats wrote: | _The first and most important question of course is to understand | that having too much WIP is in fact bad._ | | This is a well-understood concept in factories. Not enough people | today have ever been in a factory. | | It's a classic problem with manufacturing plants that make a | large number of different items. There, it's obvious - you have | racks or piles or bins of partially finished product sitting | around. Yet you can't avoid some of that, because machines have | setup and teardown times. So you make a thousand stampings of | thing A, which then wait for the next step. If you only made a | lot of 100, there would be less work in progress, but more time | the stamping machine wasn't running while the dies were changed. | If you made a lot of 10,000, the stamping machine's efficiency | would be higher but you'd have more work in progress. So, what's | the optimal lot size? | | This is a classic business school problem.[1] There's a whole | theory of this, dating back to 1913. | | Apple is famous for having botched this with their Macintosh | factory in Fremont.[2] They centered their factory around an | automated storage and retrieval system. This meant they could | buffer a lot of work in process without making a visible mess. | Wrong approach. | | [1] https://www.allaboutlean.com/lot-size-part-1/ | | [2] https://youtu.be/Dk306ZkNOuc | xupybd wrote: | There is a fantastic novel that explains this in a | manufacturing context. | | As it explained through a fictional story it's an easy read and | a great audiobook. | | The Goal by Eliyahu M. Goldratt | | I didn't fully grasp the problem of too much WIP until I read | that book. | truemped wrote: | Author here. I loved the book and encourage everyone to read | it. Use the Theory of Constraints to identify your bottleneck | and then "limit wip" or elevate it. | quickthrower2 wrote: | Do you mean you are the author of that book or an author in | general? | grzm wrote: | 'truemped is the author of the submitted post, "Limiting | Work in Progress". | truemped wrote: | I did not write The Goal ;) | grzm wrote: | Fortunately not, otherwise you wouldn't have been able to | provide us with this submission :) | billfruit wrote: | Some of such analysis forms part of a now obscure discipline | called 'Work Study'. | whatshisface wrote: | Or a less obscure discipline called "operations research." | sbayeta wrote: | This is why SMED was developed | elevation wrote: | I watched the video in [2]. I saw the automated retrieval | system, some pick-and-place machines, some final-acceptance | testing -- all aspects of the modern manufacturing processes. | Aside from having a few more humans in the loop than you'd need | with modern machinery, nothing there looks "botched." | | This article [3] suggests that Apple simply didn't have enough | demand to make the factory successful. Success would have | required additional automation such as adding pick and place | for the larger components, automating the acceptance testing. | | [3]: https://www.mercurynews.com/2018/12/17/steve-jobs-wanted- | to-... | cortesoft wrote: | Playing Factorio helps to demonstrate this. | | At its core, Factorio is about turning a few base materials | into useful things, with many intermediate parts. Everything | you build, then, is eventually competing with those few basic | as materials. | | The first time I played, I would see some base part being | produced faster than it was consumed, and my thought was I | should store the excess product, so that the factories creating | those products would not back up and stop functioning. This | would let me have a buffer, and keep those intermediate | material producing machines running at full capacity. | | Now that I had this buffer of intermediate materials that was | growing, I would try to add more factories that used those | materials for the next intermediate material. | | However, the next intermediate material would also need other | intermediate materials, so I would have to expand the number of | factories producing raw materials to feed those other | producers. However, additional raw materials were also consumed | by the factories that were ALREADY overproducing. This lead to | an attempt at a delicate balancing act, to get the number of | factories for each type exactly right. I would add some to one | material, then have to add more to another. It was impossible. | | What I finally learned is that I had to let the factories over | producing backup and stop producing. That way, more raw | materials would be leftover for the things I was short on. This | back pressure allowed the factory to self balance. | | Increasing the buffer on something is only useful if the usage | is highly variable. Then, you need a small buffer but not too | big of one. | jkhdigital wrote: | Backpressure is _the_ most important force in any production | process. Now if only I could figure out how to apply it to my | personal life... | beaconstudios wrote: | The same problem arises in logistics, job queues in | programming, and elsewhere. The study of stocks (aka buffers) | and flows (aka processes) is the domain of system dynamics. Its | a rather interesting field of study. | xo5vik wrote: | I had misunderstood this idea as minimising the WIP, but it's | about optimisation. | | Quotes: "How can I find out what the ideal WIP limit is for the | system I am in?" "After a few iterations and having recorded the | learnings in retrospectives, we collectively decided to increase | the WIP." | | This articles also references: Why limiting work-in-progress | works. https://lethain.com/limiting-wip/ | | Discussed previously | https://news.ycombinator.com/item?id=19186456 | kqr wrote: | Well, there are two important limiting cases when it comes to | minimising WIP: zero and one. | | Assuming your work is productive in the first place, zero WIP | would be bad. | | One WIP, known as "single piece flow" is actually the ultimate | optimisation in production. So from that perspective, | optimising and minimising is the same thing. | erokar wrote: | I'm surprised Kanban is only mentioned cursorily. Limiting work | in progress is one of, if not the, point of Kanban. | chaoz_ wrote: | I think term "Kanban" is misused so often, that nobody | understands what is really means. | | Totally agree with your point, especially funny how author | rediscovers that "Limiting work-in-progress is the tool every | manager and leader needs to have in their tool belt. This is | the one super power that over time will allow moving faster to | the desired goal". | | Why do literature review. | jon_adler wrote: | I find the SAFe framework describes the brilliance of Kanban | nicely [1]. I'm surprised there isn't some discussion on | queuing theory such as Little's Law [2] either, as I feel it is | also relevant. | | [1] Principle #6 - Visualize and limit WIP, reduce batch sizes, | and manage queue lengths - | https://www.scaledagileframework.com/visualize-and-limit-wip... | | [2] Little's Law - https://en.wikipedia.org/wiki/Little%27s_law ___________________________________________________________________ (page generated 2021-04-10 23:00 UTC)