In pharmaceutical operations, it is crucial that process reliability is always high and consistent. Central to this aim is timely measurement of analytical parameters. Although analysis of grab samples offers accurate results, it is time-consuming, carries the possibility of sample contamination, and does not supply continuous, real-time data. On the other hand, in-line measurement using process analytical equipment reduces the workload of laboratory staff; measures directly in the process, eliminating the possibility of false readings due to contamination; and supplies a constant stream of real-time measurements, allowing rapid corrective action when necessary. Most significantly, in-line analytical measurements enable reliable, repeatable production of high quality pharmaceutical products, batch after batch.