A universal digital control concept for end-to-end manufacturing

With the implementation of advanced manufacturing concepts (e.g., continuous operation, integration of different process routes and modular manufacturing), control of the process and the related product quality becomes more complex. Unlike traditional in-process controls and end-product testing, modern high-speed manufacturing does not allow for delays due to measurements between unit operations and requires real-time information about the material state and associated control actions. This study presents a universally applicable control concept, which offers the highest level of control together with flexibility for processing, equipment and automation. The concept can deal with a combination of batch and continuously operated process steps, manual and automated operation, different scales of equipment, and digital and manual data acquisition. It was demonstrated using a compact end-to-end manufacturing line for tablets, which included the active pharmaceutical ingredient (API) synthesis, crystallization, filtration and washing, as well as the formulation part. A suspension of API was directly fed into hot melt extrusion (HME), which was combined with direct compaction (DC). The control strategy was based on data not only from classical process analytical technology (PAT) sensors, but also from the equipment and soft sensors (e.g., the content was monitored and controlled using the soft sensors and the feeder data). The process and quality information were fed into a digital twin of the entire process, which executed the model-based control strategy.