Process Analytical Technology, or “PAT” is the term given to analytical instruments developed to measure certain attributes of product within the manufacturing process, eliminating, or substantially minimising the need for sampling for off-line analysis. This approach has several key advantages over traditional off-line analysis methods and includes process measurements in situ with instant access to data which facilitates rapid decisions during product development and manufacture. While the time between sampling and off-line results may range from minutes to days depending on the test being performed and the analytical structures in place, many PAT systems are capable of real-time measurement results enabling control decisions to be made based not just on a process recipe, but also on the true critical quality attributes (CQAs) of the material at that point in time. This allows for a more dynamic process, compensating for variabilities such as raw material variations or mechanical wear in processing components, and supports compliance with newer QA initiatives such as continuous verification. Additionally, the automated nature of PAT allows for greater data generation with minimal operator time when compared to testing samples at-line or off-line.