Analysis of Machine Breakdown and Maintenance Scheduling at a Bottling Plant in Oyo State

Equipment downtime due to unplanned machine breakdowns is a major source of production loss in Nigerian manufacturing, with bottling plants particularly vulnerable given their continuous-flow production systems. This study analyses machine breakdown patterns and develops an optimal preventive maintenance schedule for a carbonated beverages bottling plant in Oyo State, South West Nigeria. Historical maintenance records spanning 36 months covering six critical production machines are analysed to estimate breakdown frequency distributions using Poisson and exponential models. The cost of preventive maintenance is compared against the expected cost of breakdowns under varying maintenance intervals using total cost minimization criteria. Results indicate that the optimal preventive maintenance interval for the highest-criticality filling machine is every 21 days, compared to the plant's current practice of monthly maintenance, reducing expected total maintenance costs by 19 percent. For two secondary machines, the current interval is found to be more frequent than optimal, suggesting an opportunity for cost savings through schedule relaxation. A Gantt chart for the recommended maintenance schedule is developed, ensuring that no more than two machines are simultaneously out of service. Recommendations include training maintenance technicians in reliability-centred maintenance principles and digitizing maintenance records for continuous model updating. This research provides a practical and immediately applicable framework for production management in Nigerian bottling facilities. Keywords: machine breakdown, preventive maintenance, bottling plant, Oyo State, maintenance scheduling