When evaluating milking performance, monitor the number of times the units must be adjusted by operators because of slipping or fall-off. A practical goal is less than 5% of cows milking requiring correction by the operator(s). Heavy clusters, uneven weight distribution within cluster, blocked air admission holes, and cows kicking at clusters are commons causes of slips and fall-offs.

Note the stage of milking when the slips and falls occur. Flooding clusters or milklines tend to cause slipping or falling early in milking. Poor liner design, uneven distribution of weight between the four teatcups within a cluster, and cows kicking at clusters are the most common causes of slipping and falling late in milking.