Is there such a thing as lean manufacturing engineering?
Dear Gemba Coach,
I keep reading about lean engineering and lean design. Is there lean manufacturing engineering?
Absolutely. Actually, manufacturing engineering is a core element of lean and without it lean could never be, well, lean. This is a rather difficult debate so I’ll try to illustrate it by two gemba examples. Earlier this year, I visited Toyota’s Takaoka assembly line where four different models were assembled according to takt (no batching), ranging from the two-seater iQ to a family-sized Corolla, in sequence. The first astonishing feat of engineering is of course to have such diversity working with the same production tools. But what really impressed me is that operators moved seamlessly from one model to the other – without breaking their work rhythm (which was also, by the way, rather intense). A few months earlier I was watching Porsche’s assembly line which also has a high diversity in sequence, but where, in Porshe’s terms operators are “desaturated” – meaning by that that operators have long breaks in their working cycles, sometimes stopping altogether as machines perform this or that operation on the line.
Now fast forward to many of the plants I visit outside of the automotive world. Frequently, production cells or lines are still, to this day, dedicated to one single product and operators are moved from one cell to the next according to the day’s demand. In fact, operators will move from one cell to the next within the day as well, if the demand for products doesn’t saturate the cell that builds it – which, it turns out is increasingly frequent as catalogues grow with time as new products are added, but older products still remain in use or sold. In one such plant, they actually measured the production time lost in one day from shifting people around in one workshop and they came up with the figure of 18% of working time, although they now suspect the figure could probably be higher – this is 18% productivity right there and there, not an inconsequential figure when you’re competing with low cost manufacturing.
Learning and Lean
“Lean” as a word has always had many meanings, and not all of them compatible. As time passes, this is truer than ever. Human learning mechanisms are either of assimilating – interpreting the new idea so it fits your preconceptions – or accommodating – changing your mental model according to new facts. Not surprisingly, assimilating is more frequent than accommodating and much of what people discuss as “lean” has no resemblance to the lean I was taught 20 years ago. So let’s go back, for a second, to the meaning of quintessential leanness. Toyota’s central insight back then was that, due to your own misconceptions, your method of production adds unnecessary costs to the products you’re building.
If a product is built through a sequence of isolated cells, moving parts from one station to the other adds costs of (1) poor quality control, (2) moving parts around, a (3) low operator productivity, (4) batching most likely, (5) more capital expenditure than necessary, and all the other wastes. The same is true if each product is made in dedicated cells.
If we look at it from the operator’s perspective, we see huge halls full of idle stations, where the operator has to move between one station to the next. Then, at the station, we see batches of product that need to be built with dedicated equipment that, without the tension of pull, is usually poorly maintained. Finally, the operator is often abandoned with the product and has to handle all the usual 4M issues of faulty equipment, component issues, inadequate training, and vague assembly methods. The upshot is that every single product shoulders the burden of (1) oversized capital expenditure, (2) underutilized labor and (3) all the further logistics waste linked to large buildings and complex flows.
Ten years ago, the labor cost difference with low(er) cost countries remained significant. I recall extremes of 1 to 10 gaps, but mostly, if I remember correctly, the real cost difference (adjusted with all the issues of delocalizing) was something like 1 to 4. Now, as I discuss this with managers, this gap has reduced visibly and although they still estimate that labor can be found for half the hourly rate, it’s nowhere near what it used to be. This difference should be within reach, if only the added cost of capital misuse didn’t burden costs so.
Outside of automotive, most manufacturing engineers I come across still don’t get it, and they design equipment specific to the every new product. As a result, when you’re leaning the process after them, you have to work incredibly hard to integrate the new cell in an existing one, and, often, you just can’t do it. Also, to my surprise, once the manufacturing engineering “gets it” and understands the value of flexibility, it’s sometimes not so hard to do.
And then you hit product design issues. It turns out that much of the new product could indeed be built on an existing cell, but there is one specific feature that can’t – maybe even a testing issues requiring a whole new test bench. This is complicated further that as production means are often not maintained as well as they should be and the existing cell is not good enough for the product engineer’s new baby. He simply wants a new car, and will not accept that his child has to drive the old car.
Divas and Rats
What this all comes down to is teamwork, the ability to work across functional barriers; and more than just work, to collaborate intensely with the guys across the fence. First, production must work with manufacturing engineering, which in turn must learn to work with product engineering. Leanness is the by-product of the intensity of collaboration.
To intensify collaboration, we need to create spaces for mutual hands-on learning. Humans are humans because we are collaborative tool users (I mean, this is probably how we became human in the first place), so if you want people to cooperate, start by having them play together with hands-on stuff. Many of the lean engineering tools are about just that:
- Immersion in customer usage as a team
- Tear down of competitor products as a team
- Slow build of prototype parts as a team
- Cardboard simulation of the manufacturing cell as a team
- Production kaizen involving operators, but also manufacturing engineers and even product engineers.
I remember a company where the CEO had instituted as a rule that manufacturing engineers could (and indeed should) replace old machines in the plant if they could successfully increase OEE of existing equipment by 10%. What then happened is that either 10% was enough, and no need to buy a new machine, or the case was proven and the machine they ordered was very different from the one they had in mind. Why? Because 10% increase in OEE can’t be reached by simply working alone – it’s a kaizen effort than involves collaborating across functional barriers, and so better understanding each other’s issues with the equipment.
In this, manufacturing engineers have an essential role because they are the link between product design divas and production shop floor rats, and, indeed, rumor has it that in Toyota, manufacturing engineering has the greatest power in the balance.
Indeed, there is a lean manufacturing engineering, which is similar to the rest of lean – how do we work with manufacturing engineers so that they realize their own misconceptions in the way they design equipment and come to understand the need for flexibility, reliability and ease of flow that will permit the company to moderate its capital use and lean itself further.