The Hardest Part of Lean is to See the Waste
The history of lean manufacturing shows that it is usually feasible, if not downright simple, to eliminate waste from a process. This cannot happen, though, until the waste is recognized for what it is. One of Henry Ford's key success secrets was the ability to identify waste that others overlooked even though it was (with the benefit of hindsight) in plain view, and this skill is this article's key takeaway. The specific technologies or process improvements in the examples may or may not be applicable to the reader's industry, but their chief purpose is to illustrate the thought process behind them.
Overview: Waste Hides in Plain Sight
"How many of our competitor's workers does it take to change a light bulb? Four: one to hold the bulb, and three to turn the ladder." This joke is funny until we discover jobs or processes in our own workplaces that waste even more than 75% of the labor, cycle time, materials, and/or energy involved. In My Life and Work, Ford, who grew up on a farm, cited waste as great as 95%.
I believe that the average farmer puts to a really useful purpose only about 5% of the energy that he spends. …Not only is everything done by hand, but seldom is a thought given to logical arrangement. A farmer doing his chores will walk up and down a rickety ladder a dozen times. He will carry water for years instead of putting in a few lengths of pipe.
The takeaway is that, unlike poor quality, waste effort is built into the job where it is then taken for granted. The farmer would quickly notice a sick animal or pest-infested crops but, because the chores get done, he does not notice the waste of his labor. In 1926, Ford in Today and Tomorrow elaborated,
Time waste differs from material waste in that there can be no salvage. The easiest of all wastes, and the hardest to correct, is this waste of time, because wasted time does not litter the floor like wasted material.
Again, nobody notices the waste because the job gets done and, in the absence of problems such as scrap or rework, nobody thinks to question the job's design. As an example, Edward Mott Woolley described a fabric folding operation in a bleaching and dyeing factory as follows:
But all [employees] took two steps to the right to secure their cloth, returned to the tables, folded the stuff and deposited it on another pile two steps to the left. That had always been the practice; no one had ever thought to question it. (The System Company, 1911, 41)
Henry Ford wrote later that pedestrianism is not a well-paying line of work, and a simple workplace rearrangement halved the number of steps the bleaching and dyeing factory's workers had to take. The changes doubled their output, and probably reduced their physical effort in the bargain.
Brick laying, as practiced into the early 20th century, is a classic example. Masons bent over to pick up each brick, a procedure that required the worker to lower and raise most of his body weight to add 5 pounds' worth of value (the brick) to the wall. Nobody questioned the procedure because the walls got built, although the workers went home with sore muscles and relatively low pay because they could lay only 125 bricks an hour.
Then Frank Gilbreth introduced a non-stooping scaffold that delivered bricks at waist level. Masons could now lay 350 bricks an hour, and with far less physical exertion. This resulted in higher pay, lower prices for customers and higher profits for the construction companies. A YouTube video compares the before and after situations, and you can actually see a worker bending over to get each brick. As this article promised earlier, the joke about the light bulb is far less funny when we recognize that the centuries-old method of brick laying wasted almost two-thirds of the mason's labor, and therefore his working life.
Gilbreth's movies can be used today to sensitize workers, engineers and supervisors to the kind of waste motion that is built into many jobs. They also underscore the value of making videos of jobs, as long as the workers understand that the objective is to evaluate the job designs rather than the workers. It might even be instructive to have the workers mark segments of the videos of their jobs (e.g. electronically) in green, yellow and red to indicate value-adding, value-assisting, and non-value-adding activities respectively.
If we return to the light bulb joke, factories and large businesses recognized long ago that having even one worker climb a ladder to replace a light bulb wastes the time of maintenance workers, and therefore money. This is why telescoping light bulb changers were invented more than 100 years ago. It may be acceptable to climb a ladder, or use hand tools, for occasional household chores and tasks, but no manufacturing or construction business would dream of using hand-powered tools for everyday work. If dozens or hundreds of screws or bolts must be tightened every day, power tools are used.
The same basic principle, namely that almost any unscientifically-designed job consists primarily of waste, carries over into the controversy over the minimum wage in fast food industries. The underlying principles and concepts again carry over into manufacturing industries.
Would You Like Some Fries with Your Muda?
The fast food industry almost certainly contains jobs that are worth $15 or even $20 an hour. The problem is that they are buried under so much waste motion that they can pay little more than minimum wage. Customers also pay more than they should, and the franchise owner earns lower profits than he or she should. The next time the reader visits a fast food restaurant, he or she should compare its operations to Henry Ford's (1922) basic job design principle.
The first step forward in assembly came when we began taking the work to the men instead of the men to the work. We now have two general principles in all operations—that a man shall never have to take more than one step, if possibly it can be avoided, and that no man need ever stoop over.
These principles have not been applied in the fast food industry. Workers walk to get food and drinks, and then walk them back to the pickup counter. Could work slides or short conveyor belts be used instead? Also pay close attention to the amount of time the workers spend on packaging the orders. They must wrap the hamburgers, and also unfold each box into which the order is placed.
Momentum Machines offers an automated hamburger assembly line that adds sliced tomatoes and other toppings, and even packages the completed sandwich, as Dylan Love describes in Business Insider in "Here's The Burger-Flipping Robot That Could Put Fast-Food Workers Out Of A Job." Contrary to the title, however, the machine would improve fast food jobs rather than destroy them. It would certainly reduce the number of restaurant workers necessary to produce the current amount of fast food (which means each could be paid far more), but it would also reduce prices and therefore increase demand. The Luddites still walk among us, so this is a good place to address the issue of automation "versus" jobs.
Lose the Luddites
There is a centuries-old Luddite argument that automation destroys jobs. When cars were assembled by hand, they were so expensive that only the rich could afford them. The assembly line made Henry Ford's cars affordable to the middle class which meant that, even though he needed far fewer workers to build each car, he had to hire more to keep up with the widespread demand.
If this is true for a durable product like an automobile, it is even truer for consumable products like fast food. Fast food workers should therefore welcome the Momentum Machines product rather than regard it as a threat. The same goes for automated order entry kiosks in fast food restaurants, and also self-checkout stations in retail stores.
Somebody once posted a picture of an order entry kiosk with the caption, "$15 an hour minimum wage? Meet your replacement." The implied threat is that, if workers agitate for a $15 an hour minimum wage, fast food restaurants will simply replace them with machines. The truth is that, while the kiosks may displace order-takers at counters (hopefully into better jobs), they will dig those $15 or even $20 an hour jobs from under the waste. Think about it; the customer places his or her order at the counter, and the employee gives that order to those who prepare and package the food. That means the customer, and employer, are paying to do the same job twice. You can no more pay somebody a high wage to duplicate effort than you can pay him or her to walk, or wait at a stockroom to get parts.
Waste encompasses, however, far more than waste motion and waste effort. In My Life and Work, Ford added material and energy to the list:
You can waste time, you can waste labor, you can waste material—and that is about all. …Time, energy, and material are worth more than money, because they cannot be purchased by money. Not one hour of yesterday, nor one hour of today can be bought back. Not one ounce of energy can be bought back. Material wasted, is wasted beyond recovery.
It is convenient for analytical purposes, however, to break time down into waste motion and cycle time. This leaves four simple and comprehensive key performance indices for waste: (1) waste of the time of people, (2) waste of the time of things, (3) waste of material, and (4) waste of energy. We have already considered waste of the time of people, and the next issue involves waste of the time of things.
The Value-Adding Bang
Waste of the time of things translates directly into inventory per Little's Law because inventory equals throughput multiplied by cycle time. In Gemba Kaizen, Masaaki Imai pointed out that most cycle time is non-value adding.
There is far too much muda between the value-adding moments. We should seek to realize a series of processes in which we can concentrate on each value-adding process—Bang! Bang! Bang!—and eliminate intervening downtime.
A stamping machine makes a literal bang when it comes into contact with a part, and the takeaway is that the process adds value only when it transforms the part. Work that is waiting on shelves, in a warehouse, or on a container ship represents wasted cycle time. Setup, including clamping and releasing the part, also adds no value.
Only the last turn on a fastener like a screw or a bolt, i.e. the one that tightens it, adds value. The interrupted thread bolt, the kind that tightens with a quarter turn or sixth turn of a wrench, is simply a variant of the interrupted thread artillery breechblock (see photo). When your life depends on being able to shoot more rapidly than the enemy, and the value-adding bang is a literal one, that is a strong incentive to think of a way to eliminate all non-value-adding motions from the loading process. Interrupted thread fasteners now figure prominently in setup time reduction.
How to Turn One Machine Tool into Five
An advertisement by 5ME in Manufacturing Engineering shows that enormous efficiencies may easily hide in plain view. The ad points out that cryogenic conditions, as provided by liquid nitrogen, can quintuple metal cutting speeds; in other words, one tool now does the work of five. There are no cutting fluids (environmental waste), contaminated chips, or hazardous fumes or mist. The company's website cites additional benefits such as burr reduction, which is an additional saving when we recognize deburring as 100% rework. Don Graham adds in Manufacturing Engineering that diamond tools, while more expensive than carbide ones, also can work five times more quickly, and also cut more surface feet before they need replacement.
These examples, in fact, go beyond Imai's very important observation that value is added only when a tool is in contact with a part. The tool itself should never be taken for granted because, as shown above, five-fold improvements may be possible.
Waste of Materials
Henry Ford recognized long ago that any material that does not become part of the finished product is waste. Reuse and recycling were routine at the Ford Motor Company where, for example,
- Distillation of waste wood into saleable chemicals brought in $12,000 a day in an era when the dollars were made of silver. Kingsford Charcoal was among the byproducts.
- Slag from blast furnaces was converted into cement and paving materials.
- Fumes from painting operations were adsorbed and reused to the point where a gallon of solvent did the work of ten.
- Coking of coal before using it for fuel yielded valuable coal chemicals, and to the extent that Ford actually paid less than nothing for his coal. It also removed sulfur as a saleable byproduct (ammonium sulfate for fertilizer) instead of burning it to create what is now legally a pollutant (sulfur oxides).
- Ford personally identified rust in a pile of slag from his blast furnace as unrecovered iron, and therefore waste. A process change to capture iron particles increased the yield by roughly 0.5%, which is a lot of iron when one is making thousands of tons of it.
Ford also redesigned processes to minimize subsequent machining (material removal processes) because even recyclable metal scrap was waste. This is something many people do not realize because they take the need for machining for granted. Claude Jean Mege wrote in Manufacturing Engineering in July 2000:
The aerospace industry produces parts in quantities from a few units to thousands of pieces. They cut a huge amount of swarf from these parts—often, the weight of the finished part is only 15–20% of the original rough billet, so, on average, 80–85% of the aluminum is reduced to a heap of chips.
This reference adds that a manufacturer bragged that his high agility machine (HAM) ate 400 tons of aluminum per month, and that he added an extra swarf compactor to compress the aluminum chips into bricks for sale to recyclers. If we look at the above example carefully, though, we will realize that the manufacturer is essentially purchasing five or six aluminum billets, and grinding all but one into chips and shavings to be sent back for recycling. In contrast, Ford's workforce paid close attention to any metal stock that did not become part of the final product.
In one of the stamping operations six-inch circles of sheet metal are cut out. These formerly went into scrap. The waste worried the men. They worked to find uses for the discs. They found that the plates were just the right size and shape to stamp into radiator caps but the metal was not thick enough. They tried a double thickness of plates, with the result that they made a cap which tests proved to be stronger than one made out of a single sheet of metal (Ford, 1922).
Ford added the desirability of welding smaller parts together to eliminate the need to machine away material from a cast part, and additive manufacturing can now do the same even for very complex parts. In May 2014, Sarah Webster in Manufacturing Engineering cites a hybrid additive-subtractive machine that can reduce material waste from 95% (milling) to 5% (additive-subtractive manufacturing). The key takeaway is therefore that any material that is thrown away, or even recycled, constitutes waste, and attention to this supports ISO 14001 environmental management system considerations.
Make The Resource Work Twice
Fresh water that is used once, and then thrown away (or reprocessed) should attract immediate attention. As an example, counterflow should generally be used to rinse parts in electroplating or etching operations. That is, the water from the final rinse tank, as opposed to fresh water, should be used in the first rinse tank. This halves the amount of water that must be purchased, as well as the volume of the waste stream that must be treated. Merit Partnership Pollution Prevention Project for Metal Finishers in "Reducing Dragout with Spray Rinses" (1997) adds,
Using spray nozzles as part of a rinse system can significantly reduce (1) dragout of expensive and hazardous process chemicals and (2) the amount of rinse water needed. When used on parts over plating and dragout tanks, spray rinses provide a method to recover concentrated process chemicals for reuse.
Greywater is, meanwhile, waste water from almost anything but a toilet, which can then be used to irrigate landscapes or to flush toilets. In other words, water from sinks, baths, and showers is used twice before it is thrown away. Less needs to be purchased, and less needs to be sent to a waste treatment plant. Greywater reuse supports LEED (Leadership in Energy & Environmental Design) as well as ISO 14001.
Energy: The Lesson of the Firefly
Consumers rightly resented a government mandate to phase out incandescent light bulbs because this forced them to purchase what were, at the time, cost-inefficient compact fluorescent lights. Even today, CFLs tend to fail relatively quickly despite optimistic estimates of 8000-hour lifetimes. They also contain mercury, which is hazardous if the bulb breaks. Now, however, falling costs for light emitting diode (LED) bulbs will do to the incandescent bulb what Henry Ford's affordable and reliable Model T did to horse-drawn carriages.
In a 1909 article in The Engineering Magazine, "Efficiency as a Basis for Operation and Wages," Harrington Emerson actually identified the enormous inefficiency of the incandescent light bulb. Most of the electricity is converted into heat rather than light, which is not a complete waste during winter, but is worse than wasteful when air conditioning is in use. In contrast,
The fire-fly converts the hydrocarbons of its food into light with an efficiency of 40 per cent. It flashes its light at intervals, thus making it most effective by contrast with the surrounding darkness, and it emits no more light than is necessary for its purpose.
In production the fire-fly is about seven hundred and fifty times as efficient, in volume use ten times as economical, in time use twice as economical. The fire-fly is fifteen thousand times as efficient as his human rival.
Only now has technology allowed the LED to emulate the firefly by converting more than 80% of the electricity into light, and we also have sensors that turn lights off automatically when nobody is present in a room. This emulates the firefly by using light only when it is needed. The key point is, however, that the waste was recognized long ago by somebody who did not take the situation for granted. The fact that bioluminescence could produce light far more efficiently than the incandescent bulb suggested strongly that science also should be able to come up with a better method.
The same reference also pointed out the inherent inefficiency of any process that transfers heat from a hot reservoir to a cold one, which is how all steam engines and internal combustion engines work. The following observation underscores the virtues of fuel cells that convert chemical energy directly into electricity.
An oil engine may reach 30 per cent thermal efficiency, but the salmon, assuming his whole weight to be pure oil, without consuming it, uses up several times more energy than is yielded by an equal weight of oil in combustion.
The salmon uses atomic [chemical], not thermal, energy.
This is another example of not taking the use of energy for granted, and any action that reduces energy consumption supports the objectives of ISO 50001 and/or LEED.
Summary
The greatest barrier to the elimination of waste is frequently not the absence of an off the shelf technical solution, but rather failure to recognize the waste in the first place. Henry Ford's success secret consisted of (1) not taking any job for granted, and (2) paying close attention to the manner in which a job used time, material, and energy. He also taught these skills to his entire workforce as shown by numerous employee-initiated, as opposed to management-initiated, improvements. Today's manufacturers can achieve similar world-class results through the application of these principles.
William A. Levinson, P.E., is the principal of Levinson Productivity Systems, P.C. He is the author of The Expanded and Annotated My Life and Work: Henry Ford's Universal Code for World-Class Success, and numerous other books on quality, management, and productivity.
