First discovering mistakes and then preventing them… or how did that work?
Mistakes are annoying – that’s obvious. But what can we do about it?
In our article “Causes of errors and the frustrating consequences thereof” we have already talked about the reasons for errors and their consequences. But to think about the question of how to prevent this, we must first go back to the origin – back to the errors.
So where do mistakes occur? Looking at the typical product life cycle, the question is easy to answer: in every phase. But the later a defect is discovered, the more expensive it becomes. This is also shown by the rule of ten (Figure 1). This means that if we discover a defect in the late phases of the product life cycle, it costs us much more than if we discover it at the beginning of the product life cycle. The practical thing is that, in fact, 85% of all errors occur in the very early phases. That fits together, doesn’t it? Most errors happen at the beginning and these errors can then be eliminated even more cheaply.
But why does this not happen? Why do we accept the high costs only to discover an error later than we could? Most of the time the reason is “We don’t have time for error prevention”. But if an error occurs in one of the later phases, companies suddenly have all the time in the world. Because then mistakes have to be corrected forcibly. And that is exactly the dilemma. What is the consequence of this fact?
Prevent known errors
Significant improvements could be achieved by early prevention of known errors. This not only sounds logical, but can also be implemented in concrete terms. Instead, productivity is usually increased by all means. While this may seem sensible, it does not help, since small productivity increases are out of proportion to the costs of a single recall. Companies can win the most if they consistently deal with preventing known errors.
Discover unknown errors
All unknown errors, on the other hand, must be detected and analyzed as early as possible. An unknown error may (must!) therefore be made. However, it must be ensured how it can be prevented in the future so that it does not occur again. We must develop towards a learning culture in which mistakes can be discussed with all participants and everyone has a real interest in living a continuous improvement process. However, once the guilty party has been identified, the failure analysis is stopped and no one is helped. Quite the opposite: it is precisely this behaviour that leads to a people’s error avoidance strategy, in which the resulting errors are not communicated transparently but concealed.
Let us sum up our statements once again:
The fact is:
- Errors cost more the later they occur in the product life cycle
- Most defects occur in the very early stages of product lifecycle → Most defects are inexpensive to prevent
The problem is:
- We do not take care of error prevention in the early phases because we do not have time.
We still have to deal with the defects → We spend an unnecessary amount of money on fixing the defects
The result of this is:
- We need to prevent known defects
- We must detect unknown defects at an early stage, correct them and ensure that they are prevented in the future.
Sounds easy, doesn’t it? But how can this actually be achieved in practice? What do we have to do to be able to implement the measures? How can we prevent known defects and discover unknown ones? We will deal with these questions in the next articles of our Zero defects are possible series.