The Production Phase

The EUP's production phase represents the portion of the system life cycle in which the release of a system is in actual use. As the name implies, the goal of this phase is to keep your software in use until it is either replaced with a new version from a minor release such as a bug fix to a major new release or it is retired and removed from service. Note that there are no iterations during this phase, or there is one iteration, depending on how you look at it, because this phase applies to the lifetime of a single release of your system. To develop and deploy a new release of your software, you will need to run through the four development phases again, a concept depicted in Figure 6-3.

Figure 6-3. The augmented view of the EUP life cycle.

The EUP life cycle depicted in Figure 6-3 is interesting because it depicts critical concepts that aren't always clear to people new to the Unified Process. The large arrows across the top of the diagram show that once a system is released into production, you often continue working on a new release of it. Depending on your situation, work on the next release will begin either in the inception, elaboration, or construction phase. Along the bottom of the diagram, the phase milestones are indicated to make them more explicit (hence you are less likely to bow to pressure to move into the next phase even though you haven't achieved the appropriate milestone).