Maintenance and Availability Study of a Manufacturing Company: Case Study of a Flour Mill Company

The focus of this study is to carry out a maintenance and availability study of a manufacturing company using a flour mill company as a case study. To properly evaluate the maintenance activities of the company, some sets of performance ratios were used. The performance ratios used in the assessment include; equipment availability, maintenance to production ratio, equipment shutdown intensity, overall equipment effectiveness. The result obtained showed that equipment availability was 93.7%, 93.38%, 93.18%, 92.42%, 91.28%, for year 2006, 2007, 2008, 2009 and 2010 respectively. Maintenance to production ratio was 0.03, 0.04, 0.04, 0.05, and 0.06 for year 2006, 2007, 2008, 2009 and 2010 respectively. Intensity of shutdown ranged from 0.07, 0.7, 0.07, 0.08, and 0.10 for year 2006, 2007, 2008, 2009 and 2010 respectively. Overall equipment effectiveness was 86.30%, 85.10%, 84.92%, 83.33%, 81.40% for year 2006, 2007, 2008, 2009 and 2010 respectively. Comparing the results obtained, revealed the following; the availability of the mill declined with age, from 93.7% in 2006 to 91.28% in 2010. The proportion of time spent on maintenance as against production was on the increase from 0.03 in 2006 to 0.06 in 2010. The intensity of shutdown of the mill increased by the years from 0.07 in 2006 to 0.10 in 2010. The overall equipment effectiveness of the mill was unsatisfactory from the year when optimal replacement was supposed to have been done (year 2009), according to existing standards. OEE was 83.33% in 2009 and 81.40% in 2010. Further study also revealed that an average of N244 million was lost annually due to down time. For optimal availability, the most effective maintenance strategy needs to be adopted and preventive maintenance is recommended.