Software Architect's Handbook

Removing redundant code

Any software application may contain redundant code, but legacy applications, which are older and are more likely to have been maintained by a variety of people, tend to have increased instances of code that is either duplicated or no longer needed.

When taking over a legacy application, a software architect should look to remove redundant code. Reducing the total lines of code minimizes complexity and makes the software system easier to understand. Code analysis tools can help to identify some types of code that are unnecessary. Refactoring unreachable, dead, commented-out, and duplicate code will improve the maintainability of the system. Let's look at each of these types of code in more detail.