DEVELOPMENT OF VENDOR-MANAGED INVENTORY MODEL FOR SINGLE-SUPPLIER MULTI-MANUFACTURERS UNDER PROBABILISTIC LEAD TIME

• Main Author: Wahyu Amalia, Dianta
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/79359
• Institution: Institut Teknologi Bandung

Nowadays, many companies in the world have entered the competition stage between supply chain networks consisting of several companies. This phenomenon encourages companies to look for more efficient ways of coordinating the flow of goods along the supply chain. Companies can coordinate the flow of goods by increasing the integration of partnerships with suppliers. A form of partnership where both parties can maintain a high level of integration is a vendor-managed inventory (VMI). Several previous studies have concluded that VMI provides benefits for companies who implement it. However, these studies are still limited some assumptions, such as deterministic delivery lead times. Therefore, a study is conducted to develop a VMI model of one supplier and many manufacturers on the probabilistic lead time phenomenon with service level constraints. The research is conducted as a development of the VMI model published by Cahyaningrum (2010). Modeling starts from describing the relevant system, followed by conceptual modeling where cost savings received by suppliers and manufacturers is considered as the performance measure. Then the modeling continues to mathematical modeling, followed by model verification. Next, a solution search algorithm and numerical examples are made using the same parameters as the Cahyaningrum (2010) model. The development carried out in this research includes a model that can incorporate the probabilistic lead time phenomenon. Moreover, this model also uses a service level constraint to ensure that the number of demands not met from stock should not exceed a certain value set by suppliers and manufacturers. This research also includes an algorithm to obtain the optimal solution. Based numerical example, the VMI model can produce an optimal policy that provides cost savings for suppliers and manufacturers of Rp 304.550.382,46. The optimal policy generated by the model also provides a 99,6% service level of raw materials, the service level of finished products for manufacturers 1 and 2 is 99.9%, and the service level of raw materials for manufacturers 1 and 2 are 99.8%.