PW and WFI share some similarities in terms of water quality requirements, system design, monitoring and sampling. Typically, both a PW system and a WFI system are taken into account in the design of bio-pharmaceutical production facilities - in order to supply the individual user points as required. Due to the similarities between the two systems, the question arises as to whether there is not a possibility to fully meet the different water user requirements with only one combined system. We will explore together the possible benefits and also relevant challenges for the implementation of such combined systems.