System Dynamics Simulation in Medicine Supply Chain: A Case Study of Mashhad Razavi Hospital, Iran

Providing medicine as a strategic product has a special importance in every country. This research was done with the goal of managing inventories in the medicine supply chain using system dynamic approach.
The current research was carried out as a case study in Mashhad Razavi Hospital, Iran. Plavix tablet supply chain was studied in two levels including the pharmacy and the hospital. The inventory variables were identified and mathematical relations were stated for feedback loops. Then, causal loop diagram (CLD) and stock and flow diagram (SFD) were designed. The simulation was performed for a 30-day interval.
The results of Plavix tablet supply chain simulation for a 30-day interval showed a remarkable increase in the demand and decrease in inventory levels in a way that 39% of the patients were not served while some extra tablets remained at the end of the study period.
According to the cause and effect study of the simulation model, Plavix inventory problems were due to the increased demand in the studied time period and the inconsistency in the supply chain of this drug in Razavi Hospital. The proposed model of this study can help the policy makers of pharmacies and hospitals to achieve accurate prediction and coordinated decision making in ordering and safety stock holding policies.