The evils of mass production 2
I was by turns, pleased, gratified and yes, even dismayed by some of the comments from the first entry. Overwhelmingly though, I’m left with three conclusions:
- Cognitive dissonance
- Application problems and limitations
- What constitutes sub assemblies and where is batching truly unavoidable?
Let’s be fair. Some criticisms of Ron’s video were a bit over the top, reducing our credibility in the community. As I’ve said before:
According to Aronson (1996), when people are confronted with opposing beliefs or ones incompatible with their own, they are likely to ignore or negate that belief. They do this in order to convince themselves that they have not behaved foolishly by committing to false beliefs. To assure themselves that they have been wise in supporting their position, they often convince themselves that those who oppose that position are foolish and truly objects for contempt and derision (Aronson, 1996 p.184-8).
I think Ron has accomplished two things. One, many DEs already think they are lean because they’re operating on a shoe-string. Lean budget doesn’t mean lean manufacturing and judging from the comments, lean is no longer an abstract. That’s a good thing. Dissent also means you know you’re not. And that’s not a criticism but a goal. Mike (one of our few truly lean DEs) gave me plenty of dissent too.
Application problems and limitations
If one understands that lean is no longer an abstraction, one can either look for small fruitful ways to move forward or look for self-validating reasons for not being there (yet). Not being lean is not a failure. Saying you’re doomed to tread water, is. You don’t get there in a day, it’s a process. Just like you, Mike and Amy started sewing out of a spare bedroom. They had limited space and funds. They didn’t get lean by saying they had limited equipment and space. They had to look for ways to get there. Heck, most of you had a leg up on them. At least many of you have been sewing for years. Amy hadn’t. Everybody has their own obstacles. Real creativity means finding ways around them. Personally, I think that what most people think is creativity, is overrated (rant omitted). This sort of creativity isn’t.
Marguerite brought up some very valid points, the tangible reality for most everyone starting out. She mentioned the necessity of batching due to space and equipment limitations. Eric thought that was an opportunity for SMED (rapid changeover) but I disagreed. Changing needles and thread is such a hassle. It breaks your concentration and flow of operations. You can’t sew with any fluidity if you’re constantly starting and stopping. The best one could hope for was “batching” according to colorways and similarity of operations (which I’m certain Marguerite is already doing, she’s not an idiot). Still, creativity can be helpful. For example, how can one get buttonholes? I can tell you that I’d job it out to someone who did. I’ve already looked into it. I have a button holer but I don’t like it. Ultimately, the sooner you can add machines, the better it will be. It’s funny…most (batching) manufacturers think of it in terms of one machine to an operator. With Lean, it’s one operator per many machines, meaning more machines than operators. Sure, machines aren’t free but they aren’t an ongoing payroll expense either.
Her comments led to a discussion twixt Eric and I. Eric mentioned that she had some points about pressing. That when he made that vest, we pressed each seam as we went along. He thought that logically, we’d need several pressing stations in a cell (if we were to produce these vests). But that was a fallacy; his orientation to the process, led him to this “logical” conclusion. I told him no, we didn’t need to press each seam, just that we did it because he hadn’t learned seam handling skills and we didn’t have the one piece of equipment we needed, a blow press. “Blowing a jacket” means to put it on one of those body shaped steam presses. Having one of those would largely eliminate interim pressing. Using a hand iron after the fact wouldn’t work because lining seams could raise imprints topside. Being that we don’t have one, we have to design a cell with an ironing station centrally located with respect to the rest of the work area. Sill, is pressing really needed? I rarely press when I’m sewing. In industry, the only thing that’s pressed interim, are turned collars and cuffs or anything that takes a paper or metal jig (assuming one lacks automated equipment). But then the discussion of collars and cuffs almost begs the discussion of subassemblies (later).
On the other hand, I told Eric that what pressing there is, might need to be batched to keep expenses low. Keeping an iron going all day for occasional use in a limited cell, seems too wasteful. In such case, batching pressing is more mindful of energy consumption. Lean means lower costs so how can it be lean if it costs more? There’s any number of ways to look at the problem. One of us also mentioned a custom solution of smaller pressing stations, designed to the size of the work piece but this would still involve multiple irons being left on all day. In sum, no one suggests the solutions are simple. If they were, everyone would be a lean manufacturer.
What constitutes sub assemblies and where is batching truly unavoidable?
I truly do not know the answer to this question. How do we define a subassembly? I’m holding out for chest pads and linings as subassemblies, in part because they’re more interchangeable than shell/self pieces. I also think fusing could be a batching subassembly. Believe me, I’ve had plenty of spirited discussions with other lean adherents regarding subassemblies and the difficulty of avoiding batching in apparel production.
Using Ron’s video as an example, (he’s posted a follow up entry) what if he were assembling a multi-part mailer that consisted of four pieces of paper stapled together, a business card, a brochure, and a CD? I think a business card, brochure and CD would all be subassemblies regardless of whence they came. But how about those four sheets of paper stapled together? Should those be collected and stapled as a subassembly or should they be aggregated during the process of “manufacturing” and “packaging” the “product”?
Really, I’d love to get feedback on what you think defines subassemblies and where you think batching is unavoidable. I don’t mean unavoidable in your particular situation, I mean over-all, assuming you had every resource at your disposal. Textile production comes to mind -you can’t weave a yard of fabric, not with today’s technology. But you can make one-off sweaters. Likewise, single ply cutting is also largely untenable (and arguably undesirable from a cost perspective) but that wouldn’t be true of leather CAM cutting. Where do we draw the line? Is it cost, time, ROI? What do you think?