Without refactoring, the internal design—the architecture—of software tends to decay. As people change code to achieve short-term goals, often without a full comprehension of the architecture, the code loses its structure. It becomes harder for me to see the design by reading the code. Loss of the structure of code has a cumulative effect. The harder it is to see the design in the code, the harder it is for me to preserve it, and the more rapidly it decays. Regular refactoring helps keep the code in shape.
