World Journal of Engineering Research and Technology

Henry Onyebuchi*, Isaac E. Okwe and Anthony K. Leol

ABSTRACT

The Research was carried out to help control the defects seen in produced aluminium rolls in First Aluminium Plc, Six sigma method was adapted as a way to curb the defects experienced in the batches produced. Data of produced batches of aluminium of 200 pieces each was collected from the firm to be analyzed. Out of all the samples, 2 was the lowest recorded defects and 8 was the maximum. Additionally, some analysis was done on the data to graph out and locate the non-conforming samples in the batches in which samples 21, 25, 26, 28, 37, 38, 39, 42, 52 and 57 of the batch where closest to the Upper Control Limit, power outage was one of the major cause of these defected samples. At the end of the research, it was seen that the sigma level based on 20 batches produced from 2008 to 2012 was on an average of 3.55s and the defect level ranges from 10,000 to 40,000 units with a mean of 2.17 % out of a million outcomes. The results obtained requires improvement to be controlled. Additionally, based on the results obtained from the data analysis it was observed that lesser defects occurs during the beginning of the year which is due to the major maintenance done on machines in the beginning of the year. More defects was observed at the end of the year due the holidays and festivity during these times. Thus, factors that causes these defects where further broadened into power outage and poor operator?s dedication during the festive times. Checking these factors relating to these defect can help improve the quality of the aluminium by a great percent thereby keeping the sigma level at level higher than 3.55s.

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