The process analytical technology guidelines have been a hotly debated topic within the pharmaceutical industry ever since they were made public in 2004. This also holds true at Johnson & Johnson Pharmaceutical Research & Development (J&JPRD), Division of Janssen Pharmaceutical N.V. In recent years, the company has introduced PAT tools in its manufacturing operations and in its development organisation on a project-by-project basis. Several of these projects have resulted in a better insight into critical manufacturing processes and have led to significant optimisations.