This entry could be summarized by saying maybe industry doesn’t sew so fast after all. Pam gives me the opening I was looking for with her comment from Tuesday:
The black shirt most recently pictured on my site took me about an hour to actually sew, after cutting and fusing. Yes, the seams are flat-felled. Most home-sewers/enthusiasts think that is amazingly fast. Professionals may think it rather slow.
My response:
This is an interesting point Pam. I plan to write about the real costs of handling, a concept that is not measured or included in total production time in the typical factory.
In other words, your sewing “time” may not be as inefficient as you may suspect as compared to a typical shirt manufacturer because they are not using the same ruler you are to measure total time spent. The failure to include the time and cost of handling is the summary argument for employing lean manufacturing of which the tenet (in apparel) is one person sewing one item start to finish -like you do.
Industry and enthusiasts use two different rulers to quantify the length of time it takes to sew something. Our definition of time spent is entirely different and more tightly controlled. In home sewing, time is (comparatively) ambiguous -that’s not a criticism. Home sewers count the total project time, perhaps starting with cutting and stopping the clock after the final pressing is done. We don’t do that. Or we mostly don’t.
If you ask someone in the industry how long it takes to sew something like a sport coat, they’ll tell you something on the order of 28 minutes and you will ooh and ahh and be very impressed. We like saying this, puffing our chests out a bit. Yes we do. Problem is, it isn’t really true, not that we’re lying, we’re using a different ruler. The below specifically refers to a batch sewing process (meaning one person does the same operation on a bundle of cut goods over and over) and what many (enthusiasts included) think is most efficient. It isn’t but that’s another story and the meandering end point to all of this.
When we say a sport coat takes 28 minutes to sew, it means we are paying for 28 minutes of a sewing machine operator’s time to sew that coat. That doesn’t mean they’re doing work they aren’t paid for either. It means we’ve done the time and cost calculation of every single step of the sewing process -just the sewing part. We call this SAM or Standard Allowable Minutes. For the sake of simplicity, let’s say the average sewing operation takes 20 seconds (that is actually quite long) or three operations per minute. That means there are nearly 90 different seams sewn on a sport coat (there are actually more).
Now, just because we’re paying for 28 minutes of time, doesn’t mean it takes that long. You cannot throw a sport coat into a sewing line and come back half an hour later to start collecting jackets feeding off the end of the line. The very idea is laughable. The time spent handling the goods, schlepping it from place to place is either invisible or not quantified in our definition of “sewing time” because the cost of handling is perceived to be of a cost so low, it can’t be quantified. There are two kinds of handling for the purpose of this discussion.
One is in the sewing of pieces themselves and the time and cost of handling are rolled into the piece rate of sewing operators. Pick up a piece, pair it, sew it, fold it and lay it aside. It must be folded and lain neatly to reduce pressing time later on. Done with the bundle, you tie it up again, attach the bundle control tickets and place the bundle on a side table or trolley. This is where the second kind of handling comes in. A “floor girl” (or conveyor system) will pick up the bundle and transport it to the next person in the sequence because work operations are not necessarily adjacent to each other. Floor girls walk all day long, and tend to be very thin. Seriously. Anyway, the second kind of handling cost is reflected in the hourly wage paid to a floor girl. As it is low skilled, the cost is so minimal it can’t be calculated into the cost of product except as administrative overhead.
Another way time is wasted and not rolled into the total time calculated as home sewers would think of it, is waiting or resting time. There’s bottlenecks where work in process (WIP) is just sitting there with no one doing anything to it. In factories, this is perceived as mostly “free” but it’s not really. There’s costs associated with it in storage, keeping it clean and neat, inventorying the bundles to feed through the line, or rack space to hold jackets waiting for pressing, to say nothing of space requirements and utilities. It would be very interesting to tag one given unit of a product with a timer to see how long it took to process from cutting until it was completely finished. I’ve heard that some plants making commodity items take three weeks to process something start to finish. However, a three week processing time would not keep a plant manager from boasting it took them seven minutes to make the item, something a home sewer could finish in an afternoon.
So, what is “sewing time”? In the opinion of lean manufacturing adherents, sewing time isn’t a good measure of costs, the total time spent in process including handling and waiting around should be included. In this light, industrial sewing isn’t nearly as fast as the previously quoted 28 minutes. Generally, I would guesstimate that products that took longer to sew (28 minutes) have less wasted resting time than commodity products. If it takes longer to sew, it costs more (materials too), there are fewer of them so more is invested in the relatively fewer pieces and you need a faster return for your efforts. These factories are usually smaller too. This is why the opposite is also true too; commodity plants are really huge, they need the storage of WIP. Relative “efficiency” is subsidized by huge plants in low rent areas here or offshore.
In summary, I think an ambitious target for enthusiasts to shoot for is the total time it takes a good sample maker to make a product start to finish with a single needle machine and overlock. A good sample maker can make the 28 minute jacket in under three hours. Again, this doesn’t include pattern or cutting time, this is done for them. Also, while the sample maker does all of the interim pressing, the finishing (button holes, buttons, final pressing etc) is done by those work stations.
[Not wanting to bore anyone with a repeat on the evils of batch processing, aka the waste associated with “handling time”, see this entry for an impressive experiment you can do at home and then this one.]
Related:
How to sew faster pt.1
How to sew faster pt.2
How to sew faster pt.2b
How to sew faster pt.3
How to sew faster pt.4
Interesting! Some home sewing patterns have labels saying they can be made in 1 hour, or whatever. But home sewers who try those patterns say it actually takes a lot longer, and pattern companies explain that the 1 hour refers to sewing time only, it doesn’t include the handling, cutting, pressing etc. So the sewing pattern companies are using the industrial ruler to measure a home sewing project. That’s rather misleading, since a home sewer performs every operation and is generally interested in the total time for the project. Home sewers and industrial producers have different objectives and *need* to use different rulers.
Thanks, Kathleen, for shedding light on that 28 minutes. When I’m working, I’ve often thought about your comment once made about how much time is taken up with just handling the fabric. This is so true, and I’ve stopped batching when possible (limited by my machines sometimes) because I realize how much time I waste handling the fabric when I’ve put it down and have to pick it up again and find my place for the next step.
Marguerite
Love, love, love this conversation. So, if it would take a sample maker 3 hours, with one single needle and one overlock, what do you guess it would take one stitcher at a pod set up for that jacket? An hour? Is that with subassemblies being fed into the pod? AM 21st would know. I remember them saying that they would generally set up multiple pods for something this complex, for the subassemblies.
So, if one would normally estimate an operation would take 10 seconds being batched (and not accounting for handling time), as was mentioned in the forum, perhaps 20 seconds in a lean setting would be a good estimate? I just did some quick calculations, and that seems about right for my current project, although I think I can improve on that, as I’m not an exprienced machine operator. That’s why I roughly doubled the 28 minutes for the jacket to an hour in a lean setting.
Context
I was a relatively late adopter of lean sewing as we think of it based on the issue of sub-assemblies owing in part (I think) to the commonly noted arrogance of those specializing in more complex single needle assembly characterized by suits etc. I’m coming around but the matter of sub assemblies is a difficult one. I’ve had several spirited discussions with America’s 21st about it; they haven’t implemented pods with products this complex. That said, the only way I can see this working is to have three pods side by side. One for sub assemblies, one for shell/main construction and the last for finishing (pressing, buttons, tagging etc). An operator would have to start in the sub assemblies pod to construct linings, flaps etc and then move over the the other to construct the shell and then to the last for finishing.
Of this process, this is the item that has me perplexed, the matter of an operator carrying cut pieces around…there are many parts, perhaps 50 or more. It’s not a situation where you could create an inventory of interchangeable subassemblies which are added as an input to a shell because flaps etc must be cut from the same ply and matched (stripes etc) to its companion front. I’m thinking small baskets or something but workstations won’t necessarily have a place to lay these like a regular plant (which has a side table where bundles are laid). It is all very interesting and complex.
I don’t think the goal of an hour’s construction time (or possibly less) under lean conditions to be untenable but it’ll take some seriously applied industrial engineering, space and a lot of equipment to get there…
I’m starting my business with home-sewing as my production method and I would like be as efficient in this arena as I can be. Does anyone know if there is a lean mfg. for home sewers guide? It would also be helpful if there were some standards for home-sewers that would let me know how I’m faring. If the standard said it should take me 1.5 hours from initial cut to final hem to make an A-line skirt and it takes me 3 hrs., I would know that there are some improvements to my fabric handling or sewing methods to be made.
Not as far as I know. But, years ago when we did ours at home, I know that Amy tended to sew up a single garment from start to finish as the orders came in. We structured the cut piece bundles in order to minimize the amount of time that Amy had to do anything other than sewing (e.g. switching attachments, changing thread, etc).
In fact, our lean system now looks a whole lot more like our old home sewing system than the batch-mode system we implemented in between.
I’m with ya on the handling time! I just spent approx. 3 hours just cutting out and marking 2 skirts and 3 long-sleeved button-up blouses. The blouse fabric was stacked; I didn’t cut them one at a time. Other than not having a proper cutting table and not enough space, it’s another reason I don’t like cutting.
Speaking out of near complete ignorance, I am thinking out loud about this problem, knowing that far, far wiser and more experienced minds have already pondered this. But I’ll put this out anyway, in the 1-in-a-google chance that it might spark something helpful….
This is the kind of problem that gets into my head and won’t leave. (Which I love.) So I wonder: what are the possibilities of going vertical? If there’s not room for all of the input parts on the table, then what are the opportunities for vertical storage? And I also ponder: if what you are creating is a garment, then a dressform or mannequin (pinnable) is one logical way to keep everything together and organized. That solution seems extreme, but what about some kind of deconstructed/modified/cubist version of such? The goals being: make it mobile and keep it lightweight (=put on wheels; mostly wireform but some pinnable areas); help keep parts from being wrinkled to save pressing & maintain grain & quality (reduce abrasion, etc); keep parts together logically (in whatever way that makes most sense for the operators); make it so that the op. can quickly see if parts are missing/wrong/bad; include small baskets/drawers/file folders/hooks/etc so smaller items/parts are included in a well-organized manner.
Artists, architects, museum curators deal with interesting storage issues and have a few interesting tools and things they use (and lots of boring and uninteresting ones).
Perhaps this was tried waaay back when and found to be a horrible idea thought up by some amateur. But I’m always willing to throw out a bad idea just in case it sparks a good one. And what the heck — it is April Fool’s. If it’s a horrible idea, I’ll claim it was an April Fool’s joke.
I’m *such* a process person. This is a great discussion.
It’s also quite interesting to me (a home sewer) that even in industry the term “sewing time” is used so terribly imprecisely and misleading-ly. I would think (as an engineer) that “Total unit production time” would be used. (And even that is imprecise, since as Kathleen points out it doesn’t really speak to ‘paused’ or on-hold time [resting/bottlenecks/etc.]) With my overly-literal engineering mind, I would hear “sewing time” and assume that it meant *only* exactly that: the time the sewing machine was being run by an operator. Even as ‘just’ a home sewer, I know that the time I actually have the pedal-to-the-metal is a small percentage of the total time & effort it takes to complete a garment.
I guess if you called this series “How to Make Your *Process* Faster,” Kathleen, fewer people would have read it. (And if you’d called it “What Makes your Processes so durn slow?” even fewer still would have read it!) Calling it “How to Sew Faster” was much wiser.
(And it only takes a home sewer *one* of those “Two Hour!” patterns to learn that “Two Hours!” means that a marketing person has had their non-sewing hands involved in writing on that pattern envelope.)
All this took my mind back to my youth and working in a small fashion knitwear place Sigrid Styleknit. I wrote out the sequence and what job was to be done of how the garment was put together. Who it went to and in what order, the accessories used etc. also had to time the different stages for the office to do coatings for each new style as it came into season. Writing it like this makes me marvel what I actually learnt and did as I gained experience …me a young, shy , naive girl
Thinking back I was only young and straight out of school at 16 . I did an apprenticeship learning pattern making and tailoring and and left when I was about 22 before our eldest was born. A lifetime ago. …later on I wished I’d been older to understand more and appreciate the concepts more. But it did serve me well as I sewed for myself and children when it was expensive to buy ready made and have always mended.