Productivity is a key factor in achieving competitive advantage; therefore, industrial manufacturers must continuously reduce operational costs. In mosquito coil production, steam boilers are essential for the drying process, which typically requires 8–9 hours per batch and results in high energy consumption. The case study factory encountered several problems, including insufficient steam supply, uneven heat distribution in the drying chamber, and prolonged drying time. These issues increased production costs and caused defects such as deformation, breakage, and structural damage.  This study aimed to evaluate the performance of the steam boiler and drying system in order to improve production efficiency and reduce defects. Pareto Diagram analysis was employed to identify major defect types, while Why-Why Analysis was used to determine root causes. The results indicated that product deformation was the most significant defect. The main cause was insufficient steam supply resulting from scale accumulation inside the boiler due to poor feedwater quality, which reduced heat transfer efficiency.  System improvements were implemented, focusing on upgrading the steam supply control system with an investment cost of 150,000 THB. Consequently, drying time was reduced by 1–2 hours (16.09%), defect rates decreased by 8.55%, and drying costs were reduced by 32,826.82 THB.

Keywords

Steam Boiler, Drying Chamber, Process Improvement, Waste Reduction, Systems Engineering