The Optimal Inventory Policy with the Reusable Raw Material and Imperfect Items

This paper covers four topics regarding inventory models, namely reusable raw material, the EPQ model, imperfect-quality items, and the present value method. The relevant cost value used in traditional EPQ models does not include the stockholding cost of raw material, which makes such models unsuitable for investigating production. Because people in the world are attempting to reduce the impact of environmental impairment and increasing market competition, all products are manufactured from 100% reusable raw material and are screened during the manufacturing process. By taking the fixed proportion of imperfect-quality items and the time value into account and applying the present value method to analyze optimal inventory policies, this study creates a modified EPQ inventory model that is close to real life we meet. Furthermore, this model aims to promote the reputation of a company and ascertain its costs accurately

Coordination Mechanisms for Sustainable Supply Chain Management in Pharmaceutical Industry

At the beginning of the twenty-first century, the human environmental problems resulting from industrial manufacturing activities have affected pharmaceutical supply chain management. Governments have imposed legislations and policies on producers to tackle the medications recovery process. Besides, customers social pressure plays a major role in determining corporate sustainable strategies and performance measures. Creative and proactive approaches are therefore necessary to reduce the introduction of pharmaceutical wastes to the environment and to improve the sustainability of the value chain. In this dissertation, we propose different coordination mechanisms for sustainable pharmaceutical value chains inspired by traditional supply chains coordination mechanisms. For this purpose, a real case study for a generic pharmaceutical company, Generic PharmaX, is considered. We first focus on the reverse supply chain activities in order to reduce medication leftovers at customer sites. We develop a negotiation-based mechanism by the aid of a linear mathematical model to reflect the relationship between the supply chain entities. Results show that up to 28% more products could be collected if companies coordinate their operations efficiently. Moreover, the proposed coordination approaches leads to a win-win situation for the reverse supply chain entities, where each effort is rewarded. Next, we explore the role of providing incentives to customers in order to facilitate leftover returns and improve the sustainability for the pharmaceutical reverse supply chain. Coordination model is therefore presented between the producer and third-party logistics companies, responsible for collecting unwanted medications from customer zones. A technique is also proposed to share the expected saving between the supply chain entities. The experimental results indicate that introducing incentives to customers could decrease the amount of leftovers from 18% up to 6.5%. Furthermore, having a proper coordination with 3PL companies, in addition to customer incentives, could guarantee a full medication recovery. Finally, we focus on the inventory control management activities of the value chain. The effect of implementing a Vendor-Managed Inventory (VMI) system on minimizing the quantity of expired medications at customer zones is investigated. Results reveal that implementing the VMI system could improve the sustainability of the supply chain. More precisely, the amount of expired medications could reach zero against the current 18% expiration rate of shipped items. Some insights to guide the supply chain entities through the VMI implementation are also provided