Sewing itself is very fast so why does it take so long to get finished product out the door and why does it cost so much? As I mentioned in my book, you can have a much greater effect on reducing production sewing time and problems in the design phase than you can in production and today I’m going to show you how.
Sewing a seam is very inexpensive on the face of it but because sewing is measurable, that is how costs are calculated. People look at a seam and mentally put a price to it. Whether it is ten cents, a penny or tenths of a penny, it really doesn’t matter (no, it really doesn’t).
It is not sewing that costs –it’s handling. The problem with handling is that it is mostly invisible; it can’t be measured. If it can’t be measured, you’re not paying for it directly, only indirectly and in the worst ways with bad quality, delays, missing pieces, and dirtied goods. So the trick to reducing a lot of cost is to analyze your seam design to reduce handling points. It seems more effective to analyze seams for the number of handling steps and assign a value based on cost and complexity for each seam. Ideally, each seam would only be one point. More points are justified if the price points support it or the material or finish require it.
Let’s compare seam #2; it has 2 points for handling because it is first formed on a lockstitch and then moved over to the pressing station to be butterflied.
On the face of it, moving the work piece over to pressing doesn’t seem like a big deal but consider context; its complexity has doubled. The logistics of managing cut pieces and scheduling them for processing at another location has doubled. Likewise, there needs to be space at both ends for the bundles to be stored and of course, in moving pieces from place to place, it is possible that pieces are lost, dropped and dirtied or what have you. This is why it has been estimated that 60% of the time spent on a garment is handling it, moving it from place to place, and time is money.
I’ll grant you that it is quite reasonable to expect a 2 step seam to be done properly but what of an example like seam #9? This seam has a total of 4 or maybe 5 points depending. Points for each step of this seam’s formation are:
- a lockstitch
- one side overlocked, then the other
- topstitching one side of the seam.
- one side overlocked
- other side overlocked
- top stitching one side of the seam.
This seam is an example of an operation that can create logistics and scheduling roadblocks on the floor, an order of magnitude really. If a seam is this complex, a contractor will probably opt for the 5 point process just to simplify the work flow even though its costs are actually higher.
A seam like this may be too expensive to be justified if you consider your price points. You may get some push back from your contractor if you’re trying to get your costs lower. He or she will think this seam is too costly with time, logistics and resources considering the price you want to pay and may be annoyed that they are supposed to subsidize an unwarranted or superfluous operation.
So let’s say this is a perfect world, your price points justify the costs and product design requires it. Keep in mind that you could have a quality problem because the handling (remember, 5 points, 5 stages of handling for one seam) is complex and requires a higher order of logistics above and beyond. Believe me, it is one thing to organize the work order, operators and machines (to include thread changeovers) to do a product in however many stages. It is quite another thing to apply 5 handling steps for one seam. The result could be that in spite of the best intentions, the seam won’t be finished like this, and one or more steps may be skipped. It may be overlocked rather than lock stitched and then top stitched (reduced to 2 points). You don’t know. What is certain is that results may be inconsistent from unit to unit. The best solution is to use seams with the lowest number of points, meaning they can be done all in one pass.
The best course is to consult with your pattern maker and or contractor with respect to seam specifications. It is possible to use sewn samples from the marketplace but you must be very wary (this entry was inspired by a designer who was using seams she found in a $400 pair of jeans to use in her $40 jeans). Sewing costs are usually but not always a litmus test. Generally, a contractor with the kind of equipment to do seams like this all in one pass may charge more but the quality will be more consistent. Or even, two contractors with equal pricing but one lacks the equipment, may not end up being as equal with the latter having cost overages and or product shortages. Who is to know?
The lesson to all of this is to choose your seams wisely. Understand that the fees you pay are based on seam formation but only because handling -getting stuff from one sewing machine or pressing station to another- is invisible, can’t be accounted for and so, can’t be billed for. That doesn’t mean it isn’t costing you anything. Keep in mind that the more complex a seam is, and the more handling steps it takes to form it, the more potential there is for it to be done poorly, not as you specified or for pieces to be lost or dirtied in transit. Ideally, each seam should only be one point.
For what its worth, I “invented” this system of assigning handling points to seams which is not to say others haven’t thought of it only that it hasn’t (previously) been expressed in just this way. Meaning, don’t be dismayed if you search on the web and don’t find any material about it.
The full length version of this post that analyzes 11 types of seams with larger images can be found here.
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
Deconstructing a sewing class
Plant organization pt.3
Category: Lean Manufacturing