Pharmaceutical manufacturing environments have traditionally seen particle counting as a burden required to demonstrate compliance to a cleanroom standard. Now, however, Process Analytical Technologies (PAT) changes the focus to be on the final quality of the product. To achieve this, continuous facility monitoring is recommended. This follows the original intent of PAT, which is “to understand and control the manufacturing process: quality cannot be tested into products; it should be built-in or should be by design using a system for designing, analyzing, and controlling manufacturing through process measurements of critical quality and performance attributes of materials and processes with the goal of ensuring final product quality.”