The Expanded and Annotated My Life and Work

Visual Controls and Error-Proofing
The following material underscores Shigeo Shingo’s observation that a job 
that relies on worker vigilance to prevent defects will eventually produce 
defects. The manufacturer should instead error-proof the job, or apply 
Ford’s “can’t rather than don’t” job safety principle to quality as well as 
safety. It also shows that Ford used what are now known as visual controls: 
colored lights told the heat treatment operator what to do.
* * *
And then there is the pressing to take away the necessity for skill in any job 
done by any one. The old-time tool hardener was an expert. He had to judge 
the heating temperatures. It was a hit-or-miss operation. The wonder is that 
he hit so often. The heat treatment in the hardening of steel is highly impor-
tant—providing one knows exactly the right heat to apply. That cannot be 
known by rule-of-thumb. It has to be measured. We introduced a system 
by which the man at the furnace has nothing at all to do with the heat. He 
does not see the pyrometer—the instrument which registers the temperature. 
Coloured electric lights give him his signals.
None of our machines is ever built haphazardly. The idea is investigated in 
detail before a move is made. Sometimes wooden models are constructed or 
again the parts are drawn to full size on a blackboard. We are not bound by 
precedent but we leave nothing to luck, and we have yet to build a machine 
that will not do the work for which it was designed. About ninety per cent of 
all experiments have been successful.
Whatever expertness in fabrication that has developed has been due to 
men. I think that if men are unhampered and they know that they are serv-
ing, they will always put all of mind and will into even the most trivial of 
tasks.

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89
7
The Terror of the Machine
This chapter addresses concerns about repetitive labor, and it also shows 
that the Ford Motor Company was a pioneer in hiring handicapped work-
ers for meaningful jobs. The chapter later introduces modern concepts, 
such as job rotation, skill inventories, and workplace safety.
* * *
Repetitive labour—the doing of one thing over and over again and always in 
the same way—is a terrifying prospect to a certain kind of mind. It is terrify-
ing to me. I could not possibly do the same thing day in and day out, but to 
other minds, perhaps I might say to the majority of minds, repetitive opera-
tions hold no terrors. In fact, to some types of mind thought is absolutely 
appalling. To them the ideal job is one where the creative instinct need not 
be expressed. The jobs where it is necessary to put in mind as well as muscle 
have very few takers—we always need men who like a job because it is dif-
ficult. The average worker, I am sorry to say, wants a job in which he does not 
have to put forth much physical exertion—above all, he wants a job in which 
he does not have to think. Those who have what might be called the creative 
type of mind and who thoroughly abhor monotony are apt to imagine that 
all other minds are similarly restless and therefore to extend quite unwanted 
sympathy to the labouring man who day in and day out performs almost 
exactly the same operation.
When you come right down to it, most jobs are repetitive. A business man 
has a routine that he follows with great exactness; the work of a bank presi-
dent is nearly all routine; the work of under officers and clerks in a bank is 
purely routine. Indeed, for most purposes and most people, it is necessary to 
establish something in the way of a routine and to make most motions purely 
repetitive—otherwise the individual will not get enough done to be able to 
live off his own exertions. There is no reason why any one with a creative 
mind should be at a monotonous job, for everywhere the need for creative 
men is pressing. There will never be a dearth of places for skilled people, but 

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90  •  The Expanded and Annotated My Life and Work
we have to recognize that the will to be skilled is not general. And even if the 
will be present, then the courage to go through with the training is absent. 
One cannot become skilled by mere wishing.