PAT applications extract real time data from a process by employing fast and (mostly) non-invasive spectroscopic and optical technologies and translate recorded raw data into meaningful process information in order to control the process in real time. In a traditional (non PAT) approach process performance can only be assessed via the quality of the end product. Adequate performance of the process can therefore only be judged retrospectively, when the end product already may have to be rejected.

Besides process control, PAT data can be used efficiently to increase process understanding during development, validation, transfer or routine manufacturing. PAT data can be seen as a process signature allowing for in-depth interpretation, mechanistic understanding and continuous improvement of your process.

A third possibility is to employ PAT as a substitute for traditional release testing, known as Real Time Release. This approach saves laborious analytical testing and logistical efforts and shortens the cycle time of manufacturing significantly.