The single greatest problem that new programmers face (and often experienced programmers as well) is that programs don't always go the way they're planned. Once a logical error has been introduced to a program, fixing it becomes the most important concern to the developer. Unfortunately, in fixing that problem, the code often becomes dependent on the workaround, and other sections of code will have to accommodate the problem area. Eventually, what was once a small problem will have infected all other areas of code, and the developer will be drowning in the murky waters of implementation-dependent code.

Using the modular approach outlined in this article, however, the emphasis is on separating a logical piece of code from all others and exposing only the necessary functions and data to the other portions of the program. The goal becomes separation of logical components, and not simply 'getting it to work'.

Once a module is complete, the developer can forget the details of how the module itself works, and mentally remove themselves from the details, and focus on the big picture.