Many compounds are synthesised from raw materials in multi-batch and multi-ton quantities over extended time periods. The repetitious nature of the multi-batch business has proven a rich source of opportunity for process analytical technologies (PAT) applications at Roche, for over 15 years in some cases. The key focus has been the integration of the PAT applications into the existing manufacturing systems such as automation, IT, QC, QA, maintenance, and R&D, to mitigate risk and improve process efficiently. This case study, written by Dr John O’Reilly, PAT Technology at Roche, specifically looks at the approach to PAT implementation on one such process with a sodium borohydride reduction.