2.3. The UP Phases and Schedule-Oriented Terms

A UP project organizes the work and iterations across four major phases:

These phases are more fully defined in subsequent chapters.

This is not the old “waterfall” or sequential lifecycle of first defining all the requirements, and then doing all or most of the design.

Inception is not a requirements phase; rather, it is a kind of feasibility phase, where just enough investigation is done to support a decision to continue or stop.

Similarly, elaboration is not the requirements or design phase; rather, it is a phase where the core architecture is iteratively implemented, and high risk issues are mitigated.

Figure 2.3 illustrates common schedule-oriented terms in the UP. Notice that one development cycle (which ends in the release of a system into production) is composed of many iterations.