The downtime experienced in the Nigerian manufacturing sector has become a threat to its existence due to the cost implications. Despite different maintenance strategies, the results have not been too promising, hence the need to understand the factors causing downtime and effect on machine availability. 
Root cause analysis of two years breakdown data of a Beverage Company in Nigeria using the Five Why approach reviews that man and method are the predominant cause of failures in a production system which are both a measure of the organizational workforce competency.
The result shows that 95 per cent of the total downtime was due to man and method problems while a cumulative of 92 per cent of the total number of failures could be linked to man and method. Man and method issues are functions of skill of the workforce with the effect is obvious in the percentage of breakdown and the incurred downtime in restoring the failure on a machine.