A healthcare divisions inventory model for deteriorating items with a variable deterioration rate under permissible delay in payments

The deterioration of medicines is an extensive trend in the healthcare sector. There are a lot of medicines and pharmaceutical products, such as generic injectables, caplets, ophthalmic liquids, ointments, tablets, etc., that have short expirations; therefore, there is a requirement to develop methods to use them within their expiration time. Most of the public health system encounters this problem frequently occurs. To solve this problem, the authors developed an inventory model based on four features of the healthcare sector: time-dependent demand rate, holding cost, deterioration rate, partially backlogged shortages in demand, and credit period offered by pharmaceuticals. We also considered the time duration, which is free from interest on credit, and the rate of interest. However, the hospitals have the reserve money to make the payments at the beginning, but they decide to take advantage of the credit period. We validated this model by using a numerical example and explaining the sensitivity analysis.