Analysis of an Effective Inventory Policy for Catch Cover Packaging Materials Using the Wagner Whitin Method at PT XYZ
DOI:
https://doi.org/10.33197/jlscc.v4i2.3461Keywords:
wagner within, Dynamic Deterministic, InventoryAbstract
PT XYZ is a national pharmaceutical company that manufactures various ophthalmic products. The production process requires catch cover packaging materials. Based on historical analysis, the demand for catch cover exhibits inter period fluctuations with a relatively high variance level, as indicated by a coefficient of variation (CV) exceeding 30%. This condition has led the company to implement a Lot-for-Lot (LFL) ordering policy accompanied by additional safety stock as a precautionary measure against demand instability. In practice, the packaging material requirements are systematically derived through the Master Production Schedule (MPS), resulting in predetermined and deterministic demand quantities for each period.
This study aims to analyze the demand patterns of five types of catch cover and to formulate a more efficient inventory policy using a dynamic deterministic approach. The methods employed include demand forecasting using the Simple Moving Average and Single Exponential Smoothing techniques, as well as inventory policy determination using the Wagner Whitin method. The results indicate that the Wagner Whitin approach significantly reduces total inventory costs compared to the company’s existing policy. The greatest cost savings were observed for catch cover A, B, D, and E, while catch cover C showed no cost difference. Therefore, the Wagner Whitin method is proven to be more efficient in minimizing total inventory costs.
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