In this hypothetical case example,

In this hypothetical case example, a manufacturer recently upgraded its purified water generation system with a pretreatment generation system, in order to lower maintenance costs and improve reliability/production throughout a facility. The legacy purified water generation and distribution/storage system had been validated one year prior to the upgrade. The manufacturer set out to develop a sampling plan for the updated system during the performance qualification (PQ) phase. The following approaches were considered (not an exhaustive list):1. Sample all sample points (critical and non-critical)2. Sample only the sample points determined by a single system owner (not a subject matter expert, or SME)3. Sample only the sample points determined by a cross-functional team (involving designees from various departments who are not necessarily SMEs)4. Sample only the sample points determined by an SME (or SMEs) by endorsing a quality validation risk management approach, in conjunction with the support of a cross-functional team