A Real-World Example

They might seem trivial in a smaller application, but in a more complex software architecture the benefits of modularity can be enormous. One our teams once worked on a project involving more than 200,000 lines of procedural PHP code. Easily 65 percent of the time spent fixing bugs was devoted to uncovering where certain functions were located and determining which data interacted with which functions. A subsequent rewrite of that software in an OO architecture resulted in dramatically less code. Had the application been implemented in such a manner in the first place, it would have resulted in not only less development time from the outset but also the discovery of fewer bugs (the smaller the amount of code, the fewer the opportunities for problems) and a faster turnaround time on bug fixes.

Because an OO approach forces you to think about how the code is organized, learning the structure of an existing application is much easier when you are new to the development team. In addition, you have a framework to aid you in determining the appropriate location for new functionality you might develop.

Larger projects often have a multimember software development team, usually composed of programmers with varying degrees of ability. Here, too, an OO approach has significant benefits over a procedural approach. Objects hide the details of their implementation from the users of those objects. Instead of needing to understand complex data structures and all the quirks of the business logic, junior members of the team can, with just a little documentation, begin using objects created by senior members of the team. The objects themselves are responsible for triggering changes to data or the state of the system.

When the large application mentioned previously was still written using procedural code, new members of the software development team could often take up to two months to learn enough about the application to be productive. After the software was rebuilt using objects, new members of the team usually took no more than a couple of days to begin making substantial additions to the code base. They were able to use even the most complex objects quickly because they did not need to fully understand the particulars of how the functionality contained within those objects was implemented.