Abstract:
The present problematic condition of a lingerie factory was an imbalance between actual sales and production order which led to inventory accumulation. The total cost of the inventory was increased up to 15,375,570 Baht/year, or 1,281,297.50 Baht/month. This problem occurred from production planning based on only the experience of the staff.
This study aimed to forecast future demand using historical product sales data. The demand forecast would then determine the amount of necessary production. The research methodology consisted of a sale and production data collection followed by an overall demand forecast using Minitab statistical analysis. The Minitab outcome showed that Winter's method was the most appropriate forecasting model. The pyramids forecast was applied to define production order quantity at a subordinate level in each volume in order to determine the production planning and calculate the inventory cost per year.
The results revealed that the factory could determine a new production quantity in accordance with the production order and reduce inventory cost to 1,194,805.17 Baht/year, which accounted for 8.20 % of total cost.