A build consists of code pieces from various modules interacting to provide a specific functionality.
(1) Each build is designed, coded and integrated into the software structure that is tested as a whole.
(2) A typical product will consist of 10 to 50 builds. With the incremental model, something will be working within weeks, with the rest delivered incrementally.
(3) Product can be introduced into the client's organization gradually.
(4) Problems of integration, changes in requirements, "shooting at a moving target".