Optimization of Production Throughput and Quality Control Metrics: A Case Study in Home Appliance Assembly
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Abstract
The given research paper is a rather detailed quantitative study of the daily and monthly production rates and defects in the production of home appliances in the General Company of Light Industry, Iraq, in the first quarter of 2026. Three different product lines have been studied in terms of the 10-foot vertical display unit (January), 2-door display unit (February), and 3-door display unit (March). The methods of statistical process control (SPC) such as p-control chart and Pareto analysis were used to describe the defects occurrences, out-of-control conditions and the root causes. Total production volumes were 1,250, 360, and 250 units, with overall efficiencies of 96.72%, 94.17%, and 90.80% respectively. The overall rate of rejection in all three months was 4.07% (75 rejected out of 1,860 total units). The most common types of defects were injection mold (March), shortages in the quantity of the foam (all months), and external structural damage (January and March). Ishikawa analysis was applied to trace the causes systematically to materials, machine conditions, human factors, and environmental disturbances such as lack of power. Recommendations that combine Six Sigma DMAIC approach, preventive maintenance regimes and corrective process controls to operational excellence are provided.
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