1.1 ,This practice uses quality risk management (QRM) and life-cycle approach to establish integrity assurance of single-use systems (SUSs), such as but not limited to bag assemblies and liquid transfer sets for processing, storage, and shipping of (bio)pharmaceutical products. It gives recommendations to identify failure modes and risks associated with such systems and their use-cases and how to identify the relevant leak(s) of concern. Integrity assurance in this context is limited to the barrier properties of the SUS, linked to microbial integrity and bioburden control (product quality) and liquid product loss (operator and environmental contamination). The required level of integrity assurance will depend on how critical the application is and can be interpreted in different ways. Other package barrier properties different from that, such as but not limited to gas barrier properties for gas headspace preservation, are not considered.