# Optimization of Inventory Management to Prevent Drug Shortages in the Hospital Supply Chain
## 2 Related Work
### Minimization of Drug Shortages in Hospital Supply Chains  
The Canadian pharmaceutical supply chain, consisting of governments, manufacturers, wholesalers, distributors, pharmacists, and physicians, acknowledges the significance of a reliable medication supply [27] Moreover, it is obvious that there is insufficient information for accessing the drugs due to different issues, for instance the distribution system of the manufacturing [28]. However, there are instances when drugs do not reach the intended locations due to glitches in the distribution system. In instances where clients cannot access important drug products, practitioners have the responsibility of knowing the reasons for the product's unavailability, the time when the product is available, available alternatives to the unavailable drug product and the involved costs, how to obtain the unavailable product from alternative sources, and additional information detailing patients' needs and healthcare providers' needs. However, it is worth noting that it is unacceptable for hospitals to experience drug shortages [29], along with the associated costs. There are various factors that could cause pharmaceutical supply disruptions, and they include unexpected increased demands in the drug's utilization, leading to an impermanent shortage. Such a shortage ends only when the manufacturing capability increases to a level that meets the identified demand. Pharmaceutical supply disruptions are also caused when products are voluntarily recalled or discontinued by a manufacturer. Disruptions also occur when Health Canada withdraws drugs from the market or when natural disasters such as floods and storms occur. These causes are responsible for the shortage costs experienced in the hospital supply chain inventory management. One needs to understand that the costs emanate from the fact that a client could not access the required drug product at the expected time. Additionally, the costs also include the time taken to purchase the drug product from alternative sources or acquiring alternative medications representing the unavailable drug product. The inventory process needs to be planned effectively to ensure that even in instances of unpredictable natural calamities, the duration of drug shortage is minimized [30]. Improper medical inventory management and drug shortages severely disrupt the HSC, which eventually leads to health services that are impoverished while increasing costs [22]. [PERSON] et al. in [23] elucidated that many hospitals and pharmacies are subject to numerous problems as they aim to achieve proper inventory control. This is on account of the fact that they have hardly addressed how medicinal products are administered, supplied, and utilized to improve health, as well as to save lives. An additional crucial issue in the HSC as illustrated by [31] is unidentified occurrences. Such disasters generate enormous losses. In order to enhance the independence of an HSC from disasters, [PERSON] [32] proposed an inventory control model that utilizes mathematical programming methods. The suggested model takes into account multiple forms of medications, ordering size, processing time, expiration dates of products, and customer service level, not to mention the holding and storage cost [33]. The equivalent answer or solution ascertains the optimum period of preparation and inventory level in the disaster formulation phase with the lowest overall cost. However, [PERSON] [20] elucidated that this method permits a handful of measuring points to distort the prediction and neglects accounting for seasonal changes and other variables. Thus, hospitals are left exposed to high costs and avoidable waste. [PERSON] et al. in [19] supported this argument illustrating that mathematical and statistical methods are proving to be inadequate to optimize the HSC. Additionally, Cardinal Health [34] has found that manual processes and workflows in medication inventory management are not just slow and troublesome, but are actually insufficient at collecting intelligent information.