Sisay, Habtamu(PhD)Assefa, Abraham2018-07-032023-11-112018-07-032023-11-112017-03http://etd.aau.edu.et/handle/12345678/5703Concrete, because of its versatility in use, is a major component of most of our infrastructural facilities today. The quality of concrete is affected by its constituent materials, the equipment used and the workmanship in concrete production process. A better or poor concrete may be made of exactly the same ingredients based on the quality control practice of the production process. The city administration of Addis Ababa is building and administering condominium buildings around the city for more than one million house seekers around different project location of Addis Ababa. Most parts of these projects are reinforced concrete structure in which concrete takes the major proportion among the consumed construction materials. This research is carried out on the quality of concrete produced and the quality management practice to enhance concrete quality under projects administered by Addis Ababa housing project office, by taking the Koye Feche site as a case study. The research used literature review, desk study, interview with experts and analysis of compressive strength test results on samples collected from ongoing concrete production sites. Statistical quality control based on compressive strength tests conducted on selected projects reveals that, 40.4% of the test results were found to be defective based on EBCS-2:1995 compliance criteria’s. According to ACI-214 classification, 35.4% of test result based on standard deviation indicates poor quality control whereas 71.25% of the test results show poor quality control practice based on their coefficient of variations. The investigation shows that, the use of poor gradation aggregate and high silt, clay, and dust content of sand, water with impurities, problems with batching which usually called under batching and over batching are major causes of quality problems. Furthermore, lack of attentive control on each production process, lack of management commitment and poor workmanship in quality concrete production is also the most frequent problems identified by respondents. Key Words: AAHDPO, Coefficient of Variation, CQMP, Management Commitment, Quality Control, Standard Deviation, Statistical Quality Control, TQM and Workmanship.enAAHDPOCoefficient of VariationCQMPManagement CommitmentQuality ControlStandard DeviationStatistical Quality ControlTQM and WorkmanshipThesis