Increment model::

The incremental model combines elements of the linear sequential model (applied repeatedly) with the iterative philosophy of prototyping. Refer to Figure 2.7, the additional model applies linear sequences in a staggered manner as calendar time progresses.

Each linear sequence produces a deliverable "increment" of the software [MDE93]. For example, the developed word processing software using progressive paradigm can do basic file management, editing and document production capabilities provides the first increment, more sophisticated editing and document production capabilities in the second generation, spelling and grammar in the third increment, and advanced page layout capabilities in the fourth pass .

It should be noted that the process flow for any increase may include prototyping paradigm. When a stepwise model is used, the first increase is often a core product. These are the basic requirements are addressed, but many extra features (some known, others unknown) remains unresolved. The core product of the customer (or undergo a thorough review). Due to the use and / or evaluation prepared a plan for the next interval. The plan focuses on changing the core product to better meet customer needs and providing additional features and functions.