Obviously, costs would have been much higher if all sampling points were tested by a third-party laboratory, or by requiring internal laboratory QC staff to work additional hours to accommodate the analysis of validation samples over and above their already busy routine schedule.The involvement of a subject matter expert (or experts) is crucial to the development and rationalization of the sampling plan using a quality validation risk management approach, since the results of the system have shown to be in a state of control meeting current USP specifications. In addition, this quality validation risk management approach can be easily defensible under U.S. Food and Drug Administration (FDA) regulations and those of other worldwide regulatory agencies (EMA, SFDA, KFDA, WHO, etc.).This article is based on a chapter written by the author for the book Environmental Monitoring: A Comprehensive Handbook, Volume 7 (Chapter 9), published by PDA/DHI (2015).