Kassahun, Jilcha (PhD)Daniel, Ashagrei (Mr.) Co-AdvisorGebremichael, Negash2019-12-142023-11-182019-12-142023-11-182019-06http://etd.aau.edu.et/handle/12345678/20366The main aim of this research is to investigate the root causes and impact of defective yarn on spinning operation, in case of Ayka Addis Textile Company. A preliminary survey was conducted at the company by taking a five month back data, the result shows a high defect rate of yarn was present in the company. Defects are still dominant in the manufacturing industry even though the attempts by companies to implement measures to eliminate them. Measuring the effects of these defects on their contribution to losses in monetary value is likely to assist the company to identify the major causes and then they take a measure to eliminate or minimize the root causes of these defects. An investigation of the root causes of the spinning department of Ayka Adis Textile Company was conducted using a root cause analysis technique also the impact of the yarn defects in monetary value is assessed, the assessment showed the company is suffering in financial loss of around 20,000,000 birr, in 2018 budget year due to production of defects. Pareto analysis, and why analysis tools were used to discover this root causes of defects which leading to monetary loss. Also the identified frequent defects were analysed to minimize their root causes.en-USImpacts of Defective YarnAyka Addis Textile CompanyImpactsInvestigationThesis