The goal of the Production Phase is to keep systems useful and productive after they have been deployed to the user community. This process will differ from organization to organization and perhaps even from system to system, but the fundamental goal remains the same: keep the system running and help users to use it. Shrink-wrapped software, for example, will not require operational support but will typically require a help desk to assist users. Organizations that implement systems for internal use will usually require an operational staff to run and monitor systems.
This phase ends when the release of a system has been slated for retirement or when support for that release has ended. The latter may occur immediately upon the release of a newer version, some time after the release of a newer version, or simply on a date that the business has decided to end support. This phase typically has one iteration because it applies to the operational lifetime of a single release of your software. There may be multiple iterations, however, if you defined multiple levels of support that your software will have over time.