Reducing the water use of plumbing products—toilets, urinals, faucets, and showerheads—has been a popular conservation measure. Improved technologies have created opportunities for additional conservation in this area. However, plumbing products do not operate in a vacuum. This paper reviews the literature related to plumbing products to determine a systems framework for evaluating future conservation measures using these products. The main framework comprises the following categories: water use efficiency, product components, product performance, source water, energy, and plumbing/sewer infrastructure. This framework for analysis provides a starting point for professionals considering future water conservation measures to evaluate the need for additional research, collaboration with other standards or codes committees, and attachment of additional metrics to water use efficiency (such as performance).