Charged with Battery

As something of a model aircraft enthusiast, I’ve been hearing scare stories about lithium-ion batteries for over a decade – and they’re not just stories: every once in a while a model flier would leave a battery charger running in their vehicle, and suffer a fire that gutted it.

Any battery will get hot if subjected to an inappropriate regime of charging or discharging, but this kind poses additional hazards due to its chemical properties. I’m going to have to simplify quite a bit here, but basically the chemistry of the common lithium-ion cell leaves it vulnerable to a condition that is euphemistically termed “thermal runaway.”

Inside each cell is a cathode and an anode, separated by an electrolyte and a porous material called the separator.

If a component has a manufacturing defect, if it becomes damaged, if it’s short-circuited or perhaps if it’s made to work too hard, the electrolyte can catch fire – but that’s just the start. In the fire, the decomposition of the cathode and anode commonly release (among other things, if I have understood correctly) oxygen, and hydrogen. The release of oxygen in particular means that the more it burns… the more it burns. Naturally, the heat generated inside the cell means that its neighbours promptly get in on the act and the whole battery burns.

If this occurs in a confined space, such as that formed by the casing of a mobile ’phone, you get a small explosion – plus toxic gases released as the other components in the phone are subjected to extreme heat.

Oh – and lithium reacts with water. It’s not really going to be an issue by the time you notice that Samsung made you a smoke grenade instead of a telephone… but strictly speaking, you ought to use a powder extinguisher on a lithium fire.

In The Picture of Dorian Gray, Lord Henry says that “… there is only one thing in the world worse than being talked about, and that is not being talked about.”

But then, Lord Henry never heard of the Samsung Galaxy Note 7.

Last time I boarded a flight, they were talking about this ’phone:

“For safety reasons we don’t permit any model of the Galaxy Note 7 to be carried on board. If you’re carrying this device, please tell a member of the cabin crew.”

There are signs at check-in. There is coverage in magazines, on websites, on TV and radio. This is the kind of publicity that even Gerald Ratner would choke on.

Detail from the Emirates airline website

Detail from the front page at – the wrong kind of publicity

Launched on August 19th 2016, the Galaxy Note 7 was Samsung’s flagship mobile, and its specifications were impressive. Just five days later came news of a Galaxy Note 7 exploding, in South Korea. By the end of the month they had delayed shipments to South Korean carriers, although the next day the product launched in China. (Presumably this reflects a belief that the bad batteries were all to be found in a particular batch, rather than any belief that Chinese customers are inherently more fireproof or more expendable than Korean ones.)

Just a day later, Samsung announced the global recall of 2½ million ’phones, although at this stage it was voluntary. On October 6th a Southwest Airlines flight was evacuated due to smoke from a Galaxy Note 7, prompting the Federal Aviation Administration to instruct passengers not to turn on or charge the ill-fated ’phone – nor to stow it in cargo. The U.S. Consumer Product Safety Commission urged Galaxy Note 7 users to cease using their phones, and carriers including AT&T and T-Mobile withdrew them from sale.

After a series of fires in replacement devices – those that had been subjected to additional inspections and quality control measures – Samsung finally threw in the towel, suspending production of the product and then announcing its end. The withdrawal of the Galaxy Note 7 left a highly unusual gap in the market because Samsung’s rivals commonly avoid bringing out competitor products at the same time of year, so customers who received a refund had relatively few options to spend their money on. Meanwhile, Apple’s share price surged, despite a recent lukewarm reception for their latest iPhone – a device most notable for the unpopular decision to remove the headphone socket.

Part of the problem here is the very personal nature of mobile ’phones: you put a lot of personal information on them including passwords and banking details; you store photos of your loved ones; you expect people to be able to reach you; you learn your way around the quirky operating system. Nobody wants to have to delete all their personal information and preferences, and give them up. Your ’phone is closer to you, for longer, than your loved ones – and you probably sleep with it on the nightstand. The idea that it might have harmed you, and that it will be taken from you – not because you broke it or lost it but because it’s no good – that feels like a betrayal. It seems that Samsung will continue to feel the effects of this problem for a long time to come.

On Supply Chain Radio they said that the times we live in magnify Samsung’s woes, because of the perils of social media. Certainly, there have been some great jokes about Samsung’s plight (see below) but I think our interconnected age actually makes it much simpler to handle a problem of this kind. For one thing, all Galaxy Note 7 users are online, by definition: they could be reached with a message about a product recall. Contrast that with the old days, when the manufacturer of a defective car would have to take out advertisements in newspapers, to tell the world how crappy their cars were. The new approach is free, and it’s accurately targeted: it need not scare off potential customers.

Unboxing the Galaxy Note 7

Unboxing the Galaxy Note 7 [twitter user Marcianotech]

There is also the option of a software patch, delivered over the airwaves, to fix problems. Samsung tried a patch that would limit charging to 60% of capacity… but their ’phones kept on melting down, all the same.

Even when a fix can’t be achieved remotely, at least the connected nature of the surviving Galaxy Note 7’s offers a way to ensure compliance with the recall: presumably it would be simple enough to send out a software update that forces a shutdown – and once your smartphone has become a novelty paperweight (warning: keeping it near paper is probably a mistake) most users will be persuaded to swap it for something that works.

So, are all those defective telephones going to be remanufactured? No. Samsung has announded they will destroy all the returned ’phones. Given that the device sold for something like US$850, that’s an awful waste, but we’re now looking at a product that must be treated as hazardous. It can no longer be transported by air, or carried in the post. This leaves returned Galaxy Note 7’s scattered, rendering remanufacture uneconomical. Presumably, some recycling can still take place, if only to  salvage some of the more valuable metals – but almost all of the effort that went into making these ingenious devices is wasted.

Samsung Galaxy S7, burnt

Nothing beats that new gadget smell…

When Apple laptops were found to have hazardous batteries in 2006, they were quick to point out that the batteries in question had been made by Sony. Samsung has no such luxury: the Korean giant’s batteries were made by a subsidiary. Also, the remedy for Apple’s older laptops was relatively simple because the battery was removable. Samsung only recently switched over to a sealed in battery – presumably for reasons of waterproofing – and this has magnified their pain.

According to Credit Suisse, Samsung will have have lost nearly US$17 billion in revenue as a result of these problems.

Efforts to pack still more energy into a smaller, lighter devices continue.


Almost as Good as New

I broke my iPad a little while ago. I wouldn’t have broken it if I hadn’t been trying so hard to protect it: I put it in the boot (some say, ‘trunk’) of the car, so it wouldn’t be seen by an opportunist thief, and I didn’t want it to get battered by sliding around in there, so I wrapped it in a jumper… and that’s how I came to drop it: it slipped out of the folds of the jumper when I picked it up. It only fell about two feet, but onto concrete that was enough. The case didn’t protect it sufficiently (thanks, Belkin…) and I was left with an iPad with an ugly dent on one corner, and cracks in the glass surface.

iPad screen with damage at the corner

I didn’t take a picture of the damage to mine, but it looked something like this. Ouch!


This caused me to experience at first hand some of the best remanufacturing I’ve seen.

If you want an example of a product with no user-serviceable parts, look no further than the iPad: the whole thing is about as seamless as the mysterious black slab in ‘2001: A Space Odyssey’ (Only thinner, of course: Sir Jony Ive and his obsession with thinness…)

I’d never needed to put Apple’s service department to the test before, and it had been a long, long time since I visited an Apple Centre. The experience was a bit confusing because the shop was crowded with people and there didn’t seem to be anything resembling a queue. (Who are all these people? I was an Apple user before it was cool…) Eventually I managed to seize a member of staff, who briefly patronised me because I’d mistakenly said I needed to get my iPad repaired. No, no, no… I could swap it for an exchange unit, I was told. This was what I meant (I can read) but to do that, it seemed I had to make an appointment with a “genius”.

Does anybody else find this immodest term a bit ridiculous, or is it just me? (A quick Google search reveals an ITworld article entitled ‘Does anyone else want to punch the “Apple Genius” guy in the face?’ so perhaps it’s not just me being a curmudgeon, on this occasion.) Perhaps Apple’s corporate-speak just doesn’t translate very well into English. Either that or accepting a broken iPad from a customer, recording their personal details and putting it into a padded envelope is something that only their finest can do.

The “genius” in question would be free in a little over an hour, it appeared: I decided not to wait.

At the weekend, I visited an authorised reseller (thanks, KRCS) and had a much better experience. No wait required, and nobody feeling sufficiently like Oscar Wild as to declare their genius. It turned out there was some moderately clever work to be done as we had to go through the process by which the “find my iPad” functionality is switched off, since I would otherwise be tracking the location of an iPad I no longer owned. I also did a factory reset that wiped all my personal information from the device.

And so, goodbye DLXM31CVFH12 … we hardly knew you.

Now here’s the interesting thing: you might well worry that your exchanged iPad will be swapped with one that’s had a hard life. The reseller said my iPad was probably in the best condition he’d ever seen (give or take a single brief bounce on a piece of South East London pavement). What if the ‘new’ one hadn’t led such a pampered existence? No problem: the device gets not only a new screen, but a new back casing, and Apple replace all the parts that are subjected to wear and tear as well. All the buttons are replaced with new components, and the battery too.

You never really notice the memory effect in rechargeable batteries, until you replace them. The gradual decline in capacity that is inevitable with virtually every battery technology had affected my iPad, too, despite only occasional usage. At £179, my “screen replacement” really gave my mini iPad a whole new lease of life. Not only was the battery much better than I remembered, but the unit came wrapped in protective film, just as it had when it left the factory the first time. No blemishes at all; not so much as a fingerprint on it. The ‘new gadget experience’ and even the ‘new gadget’ smell, all over again. This is what remanufacturing should be: a process yielding products that are as good as new, with a guarantee to prove it.

The hardware side of the experience was superb; the software side, less so. The replacement iPad came with firmware in place that I couldn’t dislodge with a full restore. Thus, I am forced to live with iOS 9 from now on. I’d kept my iPad on iOS7 because I don’t like Apple’s more recent efforts at user interface design. I find the new, minimalist graphics rather childish.

Regardless of my wishes in this regard, that era is over for me: I have no choice but to accept the results of Apple’s fanatical yet curiously selective war on skeuomorphism. Worst of all, an iPad with an up-to-date operating system demanded an up-to-date installation of iTunes on my computer, a piece of software that has steadily deteriorated in usability as it’s been made to do more and more over the last fifteen years. Perhaps I expect too much: perhaps it’s unreasonable to expect smooth scrolling through a list of tunes when you’ve only got four processor cores and 16GB of RAM? It seems so, but if discovering the answer involves asking a “genius”, I think I’ll pass.

In ‘White Suit Economics’ I discussed how products can now be designed so as to perform well for a known period of time, but then be made to degrade artificially, so as to force the user to replace them at a time chosen by the manufacturer and not the owner. I now have an iPad that responds only sluggishly when I start typing out a message, and it informs me daily that a still newer version of its operating system is now available. Newer software is designed to run on newer hardware, of course, and this is progress: if it ain’t broke, keep on fixing it until it is.

Daily Apple update message.

A daily hard sell: install now, or later… “no thanks” is not an option.

In a world where artificial intelligence is a hot topic, Apple’s software doesn’t display much in the way of smarts. It seems incapable of recognising that when I refuse to upgrade my software fifty days in a row, I’m unlikely to have changed my mind on day 51. Or day 52.

But how about day 53?

Perhaps this is artificial intelligence after all, and Apple has reincarnated Talkie Toaster.

The Circular Economy: n, o, p, and q

Such a nice idea, isn’t it? That the byproducts from everything that you need are useful and valuable elsewhere within the system that sustains us all. No waste, no pollution.

No more throwing things away, because (other than a very few, very expensive space probes) humanity hasn’t yet worked out how to send things away.

So how do we turn something linear into something circular?

Natural systems manage to be (more-or-less) circular: the water cycle, for example: evaporation, condensation and precipitation, over and over for billions of years. Or fish in the sea: left to themselves, the various species of fish would fill all the different niches where we have now made them scarce, and natural levels of predation would merely make room for more fish.

Cyclic systems must work, because the natural world got along fine before Charles Darwin, Sir David Attenborough or the Common Fisheries Policy. Long before conscious study and intervention, many species were happily chalking up a span of a million years or more, with plenty of diversity.

Then along comes a species that supplemented the natural cycles with a new one. Animals had used tools before, but one animal didn’t merely make use of sticks and stones that happened to be lying around: man acquired the ability to think ahead, and to shape complex tools that couldn’t have occurred naturally.

I want to use the Acheulean handaxe to illustrate the point because this very early, very simple machine shows something fundamental about human technology: it’s not cyclic. If you were butchering a carcass with your handaxe and you broke it on a stubborn bone, or you decided that it had become too blunt, you had to get a new one. (You could, perhaps, chip another flake off to reveal a new sharp edge, but your axe would become smaller if you did this.) Thus, at the dawn of man, people were acting in more-or-less the same way as we do when we go to Phones4U and request an upgrade. This one’s no good: get a new one.

Flint hand axe

Prototype Swiss Army Knife, circa 750,000 BCE

You can’t recycle a broken flint handaxe. The Earth will do it for you via erosion and the compression of sedimentary rock, but that doesn’t happen on any sort of timescale that a mere species can take an interest in. Instead, you go and get more raw materials from out of the ground.

Interestingly, in the Olduvai Gorge in Tanzania where handaxes were first made, the materials were ten kilometres from any settlement. Even back then, it seems we had logistics and procurement, as well as waste.

You might be tempted to dismiss this example on the grounds that we’re better than this nowadays. It’s true that the bronze age brought us tools that could be reforged, but for the vast majority of human history the stone handaxe was the only device there was, and you couldn’t remake a handaxe any more than you can turn fired pottery back into clay, or make bread out of burnt toast.

We take the raw materials we need, make our devices, wear them out, throw them away, and start again. This is called the linear economy, and we still apply it today. For a while, recycling was an option, but nowadays many modern products are a mass of different materials, not readily or economically separated.

Technology has given us all kinds of good things like dentistry, family planning and communications. Almost nobody would advocate a return to the simpler technologies of an earlier age, but many of the things that we enjoy nowadays come with an environmental price, because they are the product of a linear economy.

Our supply chains are exactly that: supply chains, not supply loops.

Heavy machinery at a landfill site

How’s recycling working out, where you live?

You can think of the single useful life that is obtained from many materials as being like an arc: it comes out of the ground, enters into a period of usefulness, ceases to be useful, and returns to the earth. It’s an ’n’ shape.

the n-shaped economy

Under the ‘n’-shaped economy, materials describe a brief arc of usefulness, before returning to the ground

The archetype for the circular economy is an ’o’ shape, which sees items or materials going round and round ad infinitum. It’s a nice idea, but it’s wholly idealised. Getting something from nothing isn’t realistic because even if you never waste anything again, the materials you depend upon came out of the ground at some point. Statistically, we all (as citizens of planet Earth) own something like 80kg of aluminium… yet two hundred years ago, nobody had ever seen any. Recycling is essential with this costly and energy-intensive material… but it wasn’t always an option: the pump had to be primed.

The ‘o’-shaped, circular economy

The ‘o’-shaped, circular economy may be difficult to realise, with complex products

Thus, the circular economy that supersedes the ’n’ shape isn’t really an ‘o’, but more of a ‘p’. Materials must be taken out of the ground if they are to ascend into a useful cycle. 

The ‘p’-shaped economy

The ‘p’-shaped economy may be more realistic, recognising that cycles have to begin from something…

Even then, that’s not the happy ending of the story. Although your product may be more throughly sustainable, fairtrade, non-toxic, homespun, low-carbon, vegan, recycled and eco-labelled than Jeremy Corbyn’s moustache, there’s always a bit of entropy in any system. Materials wear away, or get contaminated, or mixed together in a way that changes them for good – or they get destroyed in accidents, or simply lost. If the circular economy is truly an economy, then you have to accept that people are going to buy or lease your products and take them away and use them in unanticipated ways.

The ‘q’-shaped model

The ‘q’-shaped model recognises that even though you reuse and recycle as much as possible, entropy awaits

Like zero defects or full employment, the circular economy is unattainable, but it’s a neat way to express an aspiration. In reality, it’s not an ‘o’ shape at all, but if we apply enough ingenuity we might manage a shape that looks something like “pooooq” – a shape that describes lots of useful ‘orbits’ before entropy sets in at last.

The ‘pooooq-shaped economy’

The ‘pooooq’ economy: our best-case scenario sees redesigned products being used the maximum number of times, before they eventually become unfit to serve.

I once heard a guest speaker (and I wish I could remember who it was… Professor Bernard Hon, maybe?) who told us that a car’s electric window-winder mechanism was an ideal candidate for component reuse. It’s hidden away inside the door, so the Fashion Police can’t make a fuss that it isn’t the latest type. Car window winder mechanisms are reasonably durable, because of course it would reflect badly upon the brand if they failed… but how much more would it cost to make a window actuator that was designed to last through not just the life of the car, but through the life of five cars, with the unit being extracted and refitted four more times?

Twenty percent extra, our guest speaker said. But if that’s true, who pays for the current practice whereby an end-of-life vehicle gets shredded and the parts are either melted down or burnt in the name of energy recovery?

Car window actuator

Everything you ever wanted to know about automotive window actuators may be a mere click away.

We all pay. Motorists, for sure, but in fact everyone who needs commodities such as materials and energy… which means all of us.

It seems we’re barely out of the bronze age. Some people and organisations are showing that it’s possible to be ‘greener’, but many items are no more likely to be reused than a worn out Acheulean handaxe. Of course, we’re new at this: it’s only been seven thousand years since we started working with metals.

Perhaps we’ll crack this Circular Economy thing yet – and perhaps evaluating our efforts in terms of ’n’, ‘o’, ‘p’ and ‘q’ will help.

Meet the Monstrous Hybrid

In their book, ‘Cradle to Cradle: Remaking the Way We Make Things’, William McDonough and Michael Braungart set out a manifesto of product design principles for a sustainable society, centred upon manufacturing of suitably designed products. Their vision is a long, long way off, but there are some things that can be done within supply chains right now, not out of altruism but for our own benefit: to reduce waste disposal charges, and to ensure that material supplies last longer… which means that they are likely to cost us less.

A key concept introduced by Braungart and McDonough is that of the monstrous hybrid; a product that is an unholy combination of technical and organic ‘nutrients’. Technical nutrients can be recovered by established processes such as dismantling or melting down, whereas organic nutrients are materials that form part of the organic cycle: they grow, are harvested and refined, put to use, and then they rot away when they are disposed of, becoming compost that supports the growth of new organic products.

Organic and technical nutrients

It’s like the circle of life… only without the Lion King

The trouble comes when a product is a mixture of technical and organic materials. Consider a blister pack, commonly used in the retail of small items: it features a cardboard backing, and a vacuum-formed plastic bubble that displays the product. As soon as you open up the packaging, it becomes waste, and you throw it away… but how? Is it cardboard, or plastic? Even if you try to do the right thing and separate the two pieces so they can be disposed of in different categories, there’s going to be some cardboard and glue stuck on the remains of the plastic bubble. This is one reason why a manufacturer can’t simply melt down the plastic and mould it into something else; in fact it’s far more likely that the plastic will simply become refuse-derived fuel (RDF).

Blister pack

Blister pack, featuring a mixture of cardboard and thermoplastic

Braungart and McDonough go further, pointing out that the inks typically used for printing on packaging are oil-based. Thus, composting of cardboard isn’t an acceptable solution either, as the cardboard part has become a monstrous hybrid, never to be separated. Again, burning for energy recovery becomes the most attractive option.

This is not just a problem that affects packaging, though. Consider polyester cotton garments: they’re superior to pure cotton in that they’re harder-wearing, they resist shrinkage and they crease less… but at the end of life you’ve got a mixture of materials that aren’t easily separated.

Help is at hand, in the form of emerging materials applications such as the use of starch to make disposable cutlery: plastic cutlery would be contaminated by food, and food waste would be contaminated by waste plastic… use a starch-based bioplastic and you can compost the lot – for cheaper waste disposal charges and a clearer conscience. You can make your own bioplastics right now; it’s not particularly complicated, and your main feedstock might be something as inexpensive as potato peelings – producing a material that can be moulded using existing machinery and techniques. There’s no need to assume automatically that when you specify a plastic component that means you’re dependent upon the oil industry.

Perhaps we really can remake the way we make things.

Remanufacturing Simulation

This is the final post in a three-part series arising from the talk that I did with Dr Joe on the subject of remanufacturing. (See also: Motorcycle upcycle, and Recycling: the Elephant in the Room.)

We’ve established that recycling isn’t sufficient… which means we’re going to have to get more utility out of things when they reach the end of their normal life. Perhaps remanufacturing holds the key?

Trouble is… compared to the factory, showroom, or retail environment… things at the end of life are messy. At the end of life, products get treated in unusual ways. Old phones get given to relatives, or left in a drawer; old appliances get taken to the rubbish tip, or pushed into a sinkhole. It seems that old computers are often kept because people aren’t confident about erasing all the personal information they contain. Old cars… they provide a good illustration of the extent of the problem.

You could drive a new car out of the showroom, and wreck it fifteen minutes later. Another owner might avoid accidents, and choose to keep the same model for fifteen years or more. One owner might live by the ocean, and see their pride and joy rust badly enough to ruin it in five years, while another lives in the desert and experiences no corrosion at all (although the paintwork fades, affecting its value quite quickly). Some people like “hard driving” while others seek fuel economy. Some take care to have the vehicle checked out at every servicing interval, while others treat the machine with less respect. Taxi drivers cruise around town all day, while salesmen eat up motorway miles…

Every one of those vehicles is a different prospect at the end of life, and they reach that point for different reasons. The parts that are salvageable, and the appropriate remediation strategies are completely different in each case – as are the timings involved.

Guide [1] summarised the problems as “stochastic product returns, imbalances in return and demand rates, and the unknown condition of returned products.”

What does this mean? It means if you’re a manufacturer and you’re hoping to get things back so that you can recondition them, you don’t know how long you’re going to have to wait. When end-of-life products start coming back, there’s no guarantee that people will still be interested in them when you’ve reconditioned them… and what you get back might be spoilt beyond any possibility of economic repair.

Compare that to the simple, sterile world in which you dig materials out of the ground, and turn them into all-original products as quickly as possible.

Let’s imagine that you do have a product where remanufacturing is appropriate. There are some success stories. For example, most photocopier companies don’t actually sell photocopiers anymore: they lease them, which means that they can expect to get them back at end-of-life. (Why does this work so well for photocopiers? Because the size and shape of a piece of paper isn’t going to change any time soon: the ‘guts’ of a photocopier can be salvaged, checked over and made to serve again, in an improved model with a better user interface, but the same basic core.

Kodak disposable camera

A special case: at the peak, some 92% of the ‘single use camera’ was reused… but obviously, the customer has to return this product, or they never get their pictures.

Just imagine, though, that you’re running a factory that supplies a product, and you’re hoping to do some remanufacturing. What does that mean? Well, at the beginning, you’re not doing much remanufacturing at all, because none of your products have reached the end-of-life phase… so for a while, you’re a pure manufacturer. Later, used products begin to come back, and some useful parts can be saved, and made to serve again.

That means you’re going to need to retrain manufacturing staff to perform a disassembling and checking role. You’re going to need space to store returned products, and reclaimed parts… and you’re going to need to vary the volume in which you buy or make new parts, to take into account the volume of reclaimed parts that you’re getting back… which will vary each month. If you’ve ever heard of an economic order quantity, or economic batch sizing (or if your Enterprise Resource Planning system is predicated upon those concepts) you will recognise the pitfalls that are posed by the return of an unknown quantity of parts at an unknown time, in unknown condition.

Remanufacturing is messy, in every sense of the word.

What was needed was a tool for understanding the complex nature of end-of-life scenarios, and that was the purpose of the simulation model that I originally described at the International Conference on Remanufacturing in Glasgow, back in 2011 [2]. The theory goes something like this: you use a simulation language that’s designed for constructing manufacturing simulations, but instead of simply having workpieces flowing through a factory, being assembled into a product and then quitting the system as finished goods, you send them into a loop, where they continue to circle around a ‘use phase’ submodel.

Every month, the product gets some ‘wear and tear’ assigned to its component parts, and becomes an end-of-life product if the accumulated wear is enough to break it. It’s also checked against a specified chance that it suffers an accident, and there’s a chance that products over a certain age are found to be unwanted, and leave the ‘use phase’ loop. Products then move into an end-of-life submodel where there is a specified probability that they are returned to the manufacturer. If they are, they get disassembled, and the condition of components is assessed. Those that are good enough to serve again go into the queue for component assembly, and cause a corresponding reduction in the orders for brand new components.

Basically, it’s a machine for telling you how much remanufacturing you can expect to be doing, and when… based upon the conditions that you specify. For example, you could explore a leasing-based business model (like the photocopiers) by perhaps specifying a 48-month useful life, after which there is a 90% chance that the product is immediately retired (because it’s specified in the conditions in the leasing contract) with a 100% chance that the product comes back for remanufacturing.

Model inputs spreadsheet

This spreadsheet allows the user to specify whatever model conditions they want to explore – without having to edit the model itself.

Alternatively, if the product that you’re interested in was the engine in a tank, you might say that there’s a 2% chance of accidental damage every period, a fixed 60-month service life, and an 90% chance of the engine coming back for remanufacturing when it reaches end-of-life. (Some are ruined on battlefields, get abandoned, or end up in museums, and so on…)

The result of all this modelling comes in graph form, exported by the simulation tool, to show how much remanufacturing we can expect to be doing. Back in 2007, Geyer et al [3] had predicted that the volume of remanufactured products released over time would be a trapezoidal subset of the whole, and our simulation anticipates the same result, only a little bit messier due to the randomness introduced in an effort to represent the uncertainties of real-world conditions.

Graph showing proportion of remanufacturing occurring

Predicted quantity of reused components, based upon a scenario defined within the model. It’s… kind of trapezoidal!

It suggests that you’ll only ever be able to do some remanufacturing, and will still need a source of virgin components while volume manufacturing continues. On its own, then, remanufacturing doesn’t ‘close the loop’ – and it doesn’t ‘save the planet’, although it helps out a bit. It slows the rate at which we consume resources… at the cost of additional complexity in the supply chain, and in the scheduling of operations.

(The slides from our talk can be seen on



  1. Guide, V.D.R. (2000) Production planning and control for remanufacturing: industry practice and research needs, Journal of Operations Management, Volume 18, Number 4, June 2000, pp. 467–483
  2. Farr, R. and Lohse, N. (2011) Use of Enterprise Simulation to Assess the Impacts of Remanufacturing Operations, Proceedings of the International Conference on Remanufacturing, ICoR 2011, 27–29 July 2011, University of Strathclyde, Glasgow. (Link to full paper here.)
  3. Geyer, R., Van Wassenhove, L.N. and Atasu, A. (2007) The Economics of Remanufacturing Under Limited Component Durability and Finite Product Life Cycles, Management Science, 53(1), pp. 88–100

Motorcycle upcycle

My good friend Dr Joe and I gave a talk about remanufacturing recently. I described a simulation model that can be used to predict the rate at which we might expect to get products back at the end-of-life (I’ll describe this in another post), and Dr Joe spoke about his experiences as an importer of remanufactured scooters from India.

The experience with the scooters was interesting because it showed that despite the best efforts of academics, remanufacturing remains difficult to pin down to a single definition, in the real world. I think of remanufactured goods as being returned to ‘good as new’ condition – or better, when the remanufacturing process involves building in some redesigned component or feature that hadn’t been available when the product started its first life.

For Dr Joe, though, remanufacturing had to be approached with scepticism. Some items were great when remanufactured. The cylinder heads, for example, he described as “bomb-proof”. They showed evidence of having been welded up, drilled and tapped to ensure that the spark plug was seated just right, but they never exhibited any problems. The carburettors had been extensively modified to increase the power output of the scooters, making them ‘better than new’ – in fact, the engines on the imports were considerably up-rated from their first life.

Not everything was perfect, however: some components wear significantly, deform, or fatigue during life. Wheel hubs were found to be egg-shaped, rather than round, and new ones had to be procured, there being insufficient material left to permit a machining operation. Some engine casings were found to be modern ‘fakes’ – produced by sand casting rather than the original pressure die casting process, and these were useless. On one of the first imports, an engine mounting sheared off. Some problems such as worn teeth on the kick start mechanism were dealt with by simply adding a shim at the back of the cog, to bring the teeth more fully into contact with the ratchet.

Far too much effort went into creating an item like this to permit it to simply be recycled.

So much effort went into shaping an item like this: reuse is much better than just melting it down for recycling.

An academic would simply say that these are not remanufactured, per the accepted definition of a component being as good as new, or better, with a warranty to prove it. To a businessman, however, this is simply part of the process of doing business. When you’re importing scooters of a kind that are in considerable demand and attract a high price in the UK, you can afford to tolerate a certain amount of variability – if you have the skills and capabilities to cope with the problems. Thus, newly-arrived scooters were checked over and any parts that were clearly found to be inadequate were sent back. Since each scooter required an MOT (the Ministry of Transport test that assesses the roadworthiness of all vehicles more than three years old) this provided a good way to check each machine over. Getting each machine to comply with the terms of the test was “a lot of work” according to Dr Joe.

This tells us that the scooters weren’t remanufactured – not as whole machines, or not well enough – but they contain much that is remanufactured, and even evidence of that rarest of green goals, ‘upcycling’. In increasing the power output of the engines (necessary to make them attractive to the UK market) the imported scooter was actually worth much more than when it began its first life.

(The slides from our presentation can be found here.)