The fast‐growing interest in cell and gene therapy (C>) products has led to a growing demand for the production of plasmid DNA (pDNA) and viral vectors for clinical and commercial use. Manufacturers, regulators, and suppliers need to develop strategies for establishing robust and agile supply chains in the otherwise empirical field of C>. A model‐based methodology that has great potential to support the wider adoption of C> is presented, by ensuring efficient timelines, scalability, and cost‐effectiveness in the production of key raw materials. Specifically, key process and economic parameters are identified for (1) the production of pDNA for the forward‐looking scenario of non‐viral‐based Chimeric Antigen Receptor (CAR) T‐cell therapies from clinical (200 doses) to commercial (40,000 doses) scale and (2) the commercial (40,000 doses) production of pDNA and lentiviral vectors for the current state‐of‐the‐art viral vector‐based CAR T‐cell therapies. By applying a systematic global sensitivity analysis, we quantify uncertainty in the manufacturing process and apportion it to key process and economic parameters, highlighting cost drivers and limitations that steer decision‐making. The results underline the cost‐efficiency and operational flexibility of non‐viral‐based therapies in the overall C> supply chain, as well as the importance of economies‐of‐scale in the production of pDNA.