Lean practitioners are familiar with the Toyota Production System’s Seven Wastes. Henry Ford, however, defined three wastes that are even more comprehensive and also a lot simpler than Toyota’s. “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” [1].

We can expand waste of time to encompass the time of things (e.g. cycle time, and lost production time on equipment for whose output there is a demand) and the time of people, as lost through waste motion. Anything we throw away is wasted material regardless of whether it is an environmental aspect as defined by ISO 14001:2015.

Wasted energy can be addressed by ISO 50001:2018. The workforce can learn all four wastes—time of things, time of people, material, and energy—very quickly, and will then be able to identify them on sight. Ford relied on his front-line workers to find most of the waste in his factories.  

Here is how Ford’s four wastes encompass Toyota’s seven, along with materials and energy.

1. Overproduction ties up materials, time, and energy in inventory for which there is no immediate use. Little’s Law says inventory equals throughput multiplied by cycle time, so this increases cycle time (waste of the time of things). The cost accounting system may define inventory as an asset but, in reality, it is idle cash.
2. Waiting wastes the time of people and/or things.
3. Transportation wastes the time of people, things, and energy. Transportation time is not production time so this increases cycle time. Ford replaced batch-and-queue processes with continuous, single-unit flow processes to reduce this as much as possible.
4. Over-processing wastes the time of people, things, energy, and/or materials.
5. Inventory involves the same wastes as overproduction.  
6. Waste motion wastes the time of people. Frank Gilbreth’s non-stooping scaffold proved, for example, that bending over to pick up bricks from the ground wasted 64 percent of the mason’s labor. He could lay 350 bricks an hour when the bricks were delivered at waist level, and only 125 when they were on the ground.
7. Poor quality wastes the time of people and things, and also whatever materials and energy are needed to rework or replace the nonconformances. 

The next step is to put Ford’s metrics to work. Everybody in the organization can understand easily that we can waste only (1) the time of things, (2) the time of people, (3) materials, and (4) energy. A worker who has to walk to get or move parts, or wait for them at a stockroom, will recognize waste of the time of people on sight. Ford wrote that, if he paid workers a dollar an hour—a lot of money in his time—and somebody had to wait half an hour for a 25 cent part, the part cost him 75 cents. Inventory where it didn’t belong, namely between any two operations in a Ford plant, was an immediate visual signal of a stoppage somewhere; waste of the time of things.

There are modern analytical tools, such as the Shingo process map, that can identify wasted cycle time. Suppose, for example, a Shingo map shows that a process uses fifteen minutes when its machining, heat treatment, and other value-adding operations require only five. This tells us to look for wasted time, in the form of waiting. We must also look at interfaces between processes. If we have to wait to form a transfer batch, and then wait for a hand truck or forklift to move it, that’s a lot of wasted cycle time. Time and motion studies can, meanwhile, often identify wastes of the time of people.

Another good analytical tool is the material and energy balance that is generally taught in sophomore chemical engineering courses. We first draw a control surface around an operation or an entire process, and determine what goes in and what comes out. Inputs must balance outputs in both kind and quantity, and this includes consumables as well as stock. Anything that does not come out as a saleable output is waste. If energy that goes in does not add value by transforming the work, it also is waste. I know of no material or energy waste that can hide from the material and energy balance.

People can even identify many wastes on sight if they know what to look for. As but one example, people complain about low pay for agricultural workers, low profits for farmers, and high prices for many food products. Articles that include these complaints include photos of farm workers bending over and walking to pick strawberries and other fruits. The problem is obvious in a fraction of a second to anybody who knows what to look for, because Ford wrote that no job should ever require anybody to bend over or take more than one step in any direction [2]. He added that most farm jobs, at least in his time, wasted up to 95 percent of the labor. 

Most people take machining scrap for granted even today, because material removal processes must necessarily create chips and turnings. Ford’s workers noticed them immediately, and looked for ways to reduce the necessary machining. Ford preferred to make small items and weld them to make a finished product rather than cast and then machine a large item. Norwood [3] used the phrase "the waste worried the men" when they saw any non-saleable byproducts.

Ford’s position was that, if he paid for something, he was entitled to its full value. Slag from blast furnaces became cement and paving materials. Ford distilled coal for its valuable chemicals before he burned what was left as fuel, or used it as coke in his blast furnaces. He even took exception to rust in a pile of slag, because he recognized it as iron that should have become automobiles. 

These examples demonstrate that Ford’s four wastes—time of things, time of people, material, and energy—are simpler but more comprehensive than Toyota’s, and more than up to the job of identifying and removing wastes throughout a supply chain. 

References

[1] Ford, Henry. 1922. Ford Ideals: from "Mr. Ford’s Page." Dearborn: The Dearborn Publishing Company 

[2] Ford, Henry, and Crowther, Samuel. 1922. My Life and Work. New York: Doubleday, Page & Company

[3] Norwood, Edwin P. 1931. Ford: Men and Methods. Garden City, NY: Doubleday, Doran & Company Inc.