Why Can’t We Have Bug-Free Software?

Increased complexity is the main reason why software always has bugs.

One way to think about the problem of increasing complexity is to consider the concept of entropy. In thermodynamics, entropy is a measure of the disorder in a system. In information theory, entropy is a measure of the uncertainty in a random variable–the so-called “surprise factor.” In either case, entropy expresses a system’s degree of randomness or disorder.

In software development, entropy is a measure of the complexity of the code. The more complex the code, the more difficult it is to understand and maintain. The entropy of a piece of software increases over time as we add code to it.

This is why software always has bugs: the entropy of the code keeps increasing, and at some point, the level of disorder becomes so great that the code is no longer understandable or maintainable. (Generated code is probably the worst: if you’ve ever seen code generated by a tool, you know how difficult it can be to understand.)

The only way to combat entropy is to keep the code as simple as possible. That’s why design patterns and other techniques for managing complexity are so important. It’s also why refactoring is so essential.

If you want to get started with refactoring, I recommend the book “Refactoring: Improving the Design of Existing Code” by Martin Fowler. It’s an excellent book that will change how you think about code.

And if you’d like to learn more about design patterns, I suggest you check out my LinkedIn Learning course, “Practical Design Patterns in Swift.”

In this course, you’ll learn how to use proven techniques to write cleaner, more maintainable code.

That’s all for now. Thanks for reading!

-Karoly

#cleancode #designpatterns #refactoring #softwaredevelopment