Breaking the Habit of Dishwashing
>> He was unloading his dishwasher when he froze, holding up a giant teacup in one hand, and a rather curious looking bowl, in the other. There it was!
The story of how a group of engineers re-invented the dishwasher by spending eight years of their lives dedicated to perfect a spray arm, is not only one about advanced engineering. It is one about kicking an old, stubborn habit and committing to something else, for better and for worse.
For any product, eight years of development is a long time. For a dishwasher spray arm, it is an eternity. To put this in perspective, eight years is about three times as long as it normally takes a motor company to evolve from the first doodles of a new car model, to the car being on sale in the showroom. In an age where technology moves fast, one can’t help but wonder – what took them so long?
Dishwashers originate from the professional kitchen. The proliferation of the invention is easy to grasp – doing the dishes has never exactly been considered high status nor especially emotionally rewarding, being it professional or home kitchens. It was therefore destined that this chore would be mechanized, following industrialization and the economic upswing during the post-war era.
The first dishwashers did not at all look like the ones we use today. They were cylindrical, some spherical even, and they were not tucked away behind a cupboard door. The then novel invention stood proudly on tabletops in homes. Currently this premium place is reserved for items that people find more aesthetically appealing, such as the professional knife set.
By the dawn of the 1970’s, dishwasher design had matured. It had transformed from being a spherical table top-device to a box. Industrial designers of the time did their best in camouflaging and integrating the “box” into the rest of the kitchen architecture. Mechanically, the water pump was up to five times as strong as in modern models, making it very effective, but also very energy consuming.
Although looks had changed, the part left intact was the spray arm, and as late as year 2000, the arm still remained the same. The arm was, in other words, to dishwashers what the backbone is to humans.
>> the arm is to dishwashers what the backbone is to humans
With the energy crisis of the 1970’s and a general increase in environmental awareness, the dishwasher had to change. So as smaller cars hit the streets, smaller pumps hit the dishwashers. A simultaneous evolvement to the shrinking of pumps was dish load composition, which changed greatly between 1970 and 2000. Looking through what people have been putting into their dishwashers over this 30-year period is modern lifestyle archaeology and anthropology combined.
This was exactly what Fredrik Dellby came to realize, standing there alone in his kitchen on what had earlier seemed to be just an ordinary night in November 2002. He was unloading his dishwasher when he froze, holding up a giant teacup in one hand and a rather curious looking bowl, in the other. There it was! With suspense, he opened the upper compartment of the dishwasher to see if he was right. A bird’s nest! A complete bird’s nest of different sized and shaped glasses cutlery and dishes, stacked helter-skelter on each other. He knew he had to make a few important calls in the office the day after.
Dellby’s insight was shared with his engineering team. They had all seen dish loads gradually changing. The number of loading styles had exploded, as everyone in the family had started to help with household work. And classic serving sets had been substituted with a great diversity of cookware.
Catalysts of the load change were also dining habits that had become less scheduled than before and meals contained a selection of foods that weren’t around when dishwasher design was cemented. However, for over 30 years, nobody had officially called for a new breed of dishwashers, which could partly be due to the slow progression. Yet the main reason for no one blowing the engineering whistle has to do with the way consumer testing companies conduct tests. They use something called a “standard load”. This standard load consists of a fixed number of plates, cups, glasses and cutlery, arranged in an almost militarily and disciplined fashion. This “standard load” had not been touched since the 1970’s, even though there is no such thing as a standard load in the new millennium. Industry designers and engineers had simply been adapting their machines to the standard load, not to primarily more hard-to-predict load of the actual user.
>> rather than changing the box, make the spray pattern fit the box
A load gets perfectly clean only if every surface in the machine gets wet and is sprayed with a strong water beam. Since the spray arm rotates and forms circular water spray patterns, the targeting would be a much easier affair if the chassis was changed from box to cylinder. However, modern inbuilt kitchens required a box-solution. So rather than changing the box – change the spray pattern to fit the box.
For Fredrik Dellby there was no doubt: AEG must adjust the backbone of the dishwasher – the arm.
>> old habits die slow
Anyone who has ever tried to break a habit knows that it is not done over night. Old habits die slowly – if at all. In this case, the engineers were up to a mammoth task to change a 30-year long habit of consumers and industry, and convince themselves and the people funding the project, that it was worthwhile. Without having the equivalent of a lung X-ray, which is effective when convincing smokers re-consider their choices, only equipped with the strong gut feeling of an engineer, they were up against decades of good experiences and memories of the conventional spray arm. Also on the horizon, they knew that it might be hard explaining the fruits of the endeavour to the market, since most consumers do not realize the big role the spray arm plays. Few know that it is the arm, not for instance only the detergent that determines if the dishes come out shiny or matte.
>> to make things perfect, you have to fix things that in some way work
As if the case was not hard enough, people that historically had tried to come up with alternatives to the old spray arm hadn’t exactly experienced a career boost as a result of it. In the pile labelled “buried and forgotten”, one can find solutions such as having fixed spray-nozzles mounted on the inner wall of the dishwasher. Another interesting proposition was to have arms that used electric motors to “move around” back and forth in the machine, and that way, reach every nook and cranny of the dish load. Let’s just say that the simplest place is often a good place to look; the dishwasher is no exception.
“If it ain’t broke, don’t fix it”, they say. And there is some truth to that. However, to make things perfect, you have to fix things that in some way work.”/Fredrik Dellby, Vice President Modularisation. The first step in bringing the new arm to life, was unleashing the persuasive powers of Mr. Dellby. It meant that the project got surprisingly fast go ahead, considering the high stakes and slim chances of the endeavour. A team spread out in Italy, Germany and Sweden was given the task to create the most efficient spraying arm ever made.
>> this arm did not behave like spray arms are expected to
The team estimated to be in the challenge for the long haul – in other words, two years… Or so they thought.
The Dellbyan jumpstart to internally rally the crew pay dividends almost immediately as the first prototype left the 3D-printer already a few weeks later. It was when the team started the actual testing, that the pace slowed considerably. This arm did not behave like spray arms are expected to. It seemed to have a life of its own.
The well-rehearsed systemized testing process, which works perfectly well for the more predictable traditional spray arms, had to be abandoned. If you wanted to fix something that worked, you also had to fix the testing process, it appeared. The prototype looked a bit like a traditional spray arm, but with the difference of having a satellite arm mounted on it on one end. The idea was not new, but no one had ever made it work. It had always been more of an aesthetic feature that had come and gone. The engineers at AEG were despite setbacks confident that the way forward was to have a slow moving larger arm, and a fast, rotating satellite arm mounted on it. They knew it could work. Now they just had to make it work.
>> water and mechanic calculations just don’t mix
What makes designing an arm for a dishwasher complex is that it is powered by water. This is the reason to why many attempts to power it with a more controllable alternative, for instance an electric motor, has never been successful.
The water flow that propels the arm also goes into the spray arm where the water gets pressurized before being pushed through the narrow nozzles, coming out as a very sharp and concentrated water beam. The parameters going into calculating all these events is close to rocket science. Water driven mechanics and math just don’t mix. Computer simulations of the latter have produced an equation that only to a fair extent can predict these patterns, and it is over ten pages long. To add to the complexity, the operation of the arm is also affected by how the machine has been loaded and if it’s full or half full.
>> I guess my wife loves me
The first step to changing any old behaviour is to decide to change. Fredrik Dellby had taken the decision, gotten the resources needed and rallied a team. The other important component in change is dedication and keeping spirits up.
“People take work home. The difference with me is that I tested the arm in the shower room. I guess my wife loves me. ”/Engineer on the team
However, the trials in the lab and testing of the arm – even in some cases in the home bathrooms of employees – proved cumbersome and it is safe to say that spirits were not on a ten out of ten every day of the week.
In order for the team to get to the next level and re-discover their motivation for the task, they had to step out of the kitchen and into the world of arms. And anywhere they looked, they saw how arms played a major role.
>> human hands and arms do not work in a very systemized way
In martial arts, mastering the technique to focus all the power in the arm for a short moment and onto a distinct surface is what splits a thick plank or a brick. For a spray arm to get the dishes clean it is to do the same. It needs to be able to hit the dirt once with a strong beam, rather than repeated times with a weaker beam.
Another key insight was that human hands and arms do not work in a systemized way when for example washing a plate. If you were to graphically track the movements, it would be a series of non-perfect ellipses, being drawn randomly.
This led to the understanding that traditional dishwasher arms simply were too rigid and too predictable while the dish loads were anything but predictable. The arms were precise, but so precise that they tended to miss cleaning all of the not so precisely loaded dishes. The trick was to get the arm to operate in more irregular fashion. Perfection, in this case, was to create imperfections.
The task of designing something that is half random, half precision looked hard on paper but was even harder in practice. It is always a challenge to simulate how something works in a real situation, so the learning curve for simulating something like this was both steep and long.
“With determination comes results, and in some way, the function of the arm itself pretty much wraps that up. It focuses on the problem once, then moves on to the next. Just like us engineers I guess. Let’s just hope now that the world understands the value of a good arm.” / Fredrik Dellby
Fredrik Dellby, Vice President Modularisation
