Process intervention decisions in biomanufacturing under lead time constraints

Abstract

We analyse the challenges and trade-offs associated with production speed, quality, and lead time constraints in biomanufacturing purification operations. In particular, lead time constraints during purification pose a critical challenge in practice because the safety and quality of intermediate products deteriorate when the production time exceeds a certain predefined value. We analyse purification operations where the biomanufacturer can influence production speed and batch quality by investing in specific purification interventions. We consider two types of interventions: Type 1 interventions, which improve quality without affecting processing time, and Type 2 interventions, which improve quality at the expense of slower processing. Using a stylised model based on queueing networks, we characterise the structure of optimal policies. We show that the optimal policy for both Type 1 and Type 2 interventions is of the threshold type, but the structure of the thresholds depends on the type of interventions and relevant costs. Our analysis provides insights into optimal process intervention policies and when the lead time constraints limit system performance.