top of page

Human error behind accidents? Think again (Design for Error – Part 1)

Human error is often identified as a cause of industrial accidents. While it might appear to be plausible, such high statistics (upwards of 70%) indicate something amiss in the data.

Have you ever wondered how did you miss turning off those lights, or turning off the stove? Worse still, have you ever forgotten to lock the door of your house or vehicle? We all have been in situations when looking back, we think of ourselves as being foolish at the time of committing such mistakes. People sometimes miss fairly visible cues. Why do we do that? Is that an outcome of our physical or mental limitations?

It isn’t all human error

Don Norman, an expert in the field of human-centric design, thinks otherwise. According to him, it’s a fault with the design itself. Yes, you read that right. Many products that we interact with every day aren’t designed to counter human errors. As an example, when a bridge collapses, the investigative team springs into action. They might end up ascertaining that the failure was due to a particular engineering problem and they go on to improve in future designs. Why then is a similar approach is to be avoided when faced with human error? Is it only the fault of the user or is it caused by the way some things are designed? Let us then, explore this interesting field of ‘Design for error’.

We all can identify with the following scenario. You are in a meeting and should be noted every point in detail. Except, you fade out of the discussion, and spring back in after a while. You continue with your task, hoping not to have missed anything. Basically, you are comforting yourself for that mental ‘slip’. Now, will you empathize with someone on your team, should they end up being that person? Do you care to understand if your junior at work should doze off while working? In a normal office environment, it isn’t surprising of a person is tasked with continuous work and expected to complete them correctly and on time. Why then, should such understandably common errors be frowned upon, and employees rapped for the same.

To err is human, or is it?

Workers are often faced with the daunting task of handling multiple issues and mostly working for long periods of time. As such, a little interruption might lead them to commit errors. A somewhat negative view of human errors does contribute to making it a taboo. So what do most workplaces have such errors that occur due to distractions? Punishment. Levy fines, re-education or even a public blame and shame. While it may help the employer feel good about having ‘tackled’ the situation, such errors are bound to occur, again and again.

So how can the real cause of such errors be known and corrected? Well, in quality departments within any given company, there is a tried and tested method that researchers use to find out the cause of a product failure – Root cause analysis. When a machine breaks down, or when a part fails, the investigative team uses this model to go to the ‘root’ of the problem by repeatedly asking questions. Why did it break down? What caused the part to fail? Where in the machine did the snag occur? Why did the wires disconnect? You go on until you reach a point where the first problem occurred. Such analysis is also carried out in situations involving humans. Except, unlike in the previous example, when a question leads to a worker, further reasoning stops. Once the problem is traced to a human error, all further questioning is halted. And this is systemic in nature. You can only guess the magnitude of this crack in judgment when even defense departments fail to realize beyond a human error.

Why do we err?

Developed by Sakichi Toyoda and made famous as part of the ‘Toyota Production System’, the ‘five whys’ have helped the company reach gold standard in product quality. How do they do it? By asking a simple question, repeatedly. Why? Of course, one doesn’t stop when they reach the fifth iteration as the name indicates. This is supposed to nudge the investigator to pursue the matter beyond a couple of issues and strive to reach the root cause. Let us take an example of a plane crash.

Why did the plane crash? – It went in an uncontrolled drive

Why didn’t the pilot reverse the dive? – Because he couldn’t start the recovery immediately

Why was he unable to do so? – Because the pilot might have been unconscious

Why was he unconscious? – Because of a lack of oxygen

Why was he deprived of oxygen? – Maybe it was a design flaw

As you just saw, by merely continuing in our quest to find the real reason, we went ahead of a human error (pilot not recovering the dive). If this analysis appears so simple in nature, why don’t we do it everywhere? The answer is attitude! Certain workplaces develop a culture that is resilient to change. More so in the management, the task of accepting that systems need to be redesigned to prevent human errors is a tough ask. Many such analyses are conducted and put in the backburner. The story goes on, only to repeat in the future.

It isn’t only a management problem. Many workers blame themselves for the error. They assume that since they are so good at carrying out the said task, it should be only their foolishness and overlook that can cause any misstep. But how is anyone so sure of their abilities? And more necessarily, why isn’t anyone challenging this position? Surely, a little tweak in design may help to overcome such errors permanently, but alas.

What makes us commit errors?

Blame the machines! Partially, that is. The way they are built, these machines and other consumer products are mostly inclined to serve their main purposes. An oven is designed to primarily heat things up and bake. The one thing that designers overlook is the need to design for humans. With the sole focus laid on completing the task, designs introduce rigidity in a machine’s functionality, thus forcing the user to serve the machine by providing the exact input, every single time.

Human beings are naturally creative. By tying them to a repetitive, not to forget, a boring task that has to be completed over many hours, we risk making them gullible to commit errors. However, in the recent past, such activity based design of systems has given way for a more human-centric design. But there’s another aspect that unfortunately we are ourselves to blame for.

Many of today’s commercial establishments place a premium on time. No guess on what that means for the employees. High expectations, environmental factors, and other expected & unexpected distractions create stress on a worker to handle the job correctly and finish it on time. Failure to do so would mean a loss of money for the business and who would like that. Remember the state of nurses and doctors, running around the hospital, treating patients, registering medicine exactly to the patient as intended. Also, those who deliver goods and packages, racing against time to complete all the scheduled deliveries. People manage most of the time, but when they trip, they face the music for the very behavior that drives them to complete their job otherwise.


  • This series is a summary of Chapter 5 (Human Error? No, it’s Bad Design) from the book ‘The Design of Everyday Things’ by Don Norman

  • You can also listen to this insightful podcast by NPR Hidden Brain to understand how our minds work under stress –


Post: Blog2_Post
bottom of page