The major advantage of the incremental model is that it generates a working application faster and earlier during the software development life cycle; however, problems can occur with iteration phases if not implemented correctly, and developmental costs can be high. For it to be successful, the entire system must be clearly defined before it is broken down and developed in incremental models.
The flexibility of the incremental model makes it easier to test and debug compared to other software development models. Since only small changes are made during each incremental phase, software developers can rigorously target and test each module within the larger application. But if poorly implemented, each phase of the iteration will be rigid and will not properly overlap with the other phases causing problems that were not apparent in earlier iterations.
The incremental model drastically lowers the initial delivery cost but the resulting cost of developing the entire application will likely be higher compared to the waterfall model. Breaking down the software into smaller modules allows developers to constantly receive feedback regarding each release of the product. This model can only be applied to large software development projects because it would be impractical to break down a small application into smaller modules.
The incremental model is also referred to as the iterative life cycle model because each module has to pass through a requirements, design, implementation and testing phase. It is mostly used when the application has to be launched as soon as possible.