Equipment performance evaluation in a production plant of traditional Italian cheese

Overall equipment effectiveness (OEE) is a metric that evaluates the effectiveness of a manufacturing operation. This study investigates the relationship between the factory management and the operation of a traditional Italian cheese production line. The analysis of failure and repair data of the line over a period of 26 months was carried out. Descriptive statistics at machine and at line level were computed. In addition, the factors availability (A), performance efficiency (P), and quality rate (Q) of the OEE were calculated. Results show that: (a) the OEE performance of the line is low (76.47%), considering the target of 85%. The main causes are speed and downtime losses, (b) the availability of the line is 88.41%, whereas the maintenance time ratio is 0.1309. Thus, although availability is acceptable, the maintenance time ratio of the line is high and should be optimised with the adequate maintenance policy. (c) Every 8.5 hours there is a failure in the production line that ranges between 0 and 1885 minutes. The zero minute indicates that after completing the repair process, a new failure immediately occurred on the line. (d) The mean time to repair (TTR) a failure is 67 minutes, which ranges between 5 and 300 minutes, and (e) the minimum mean time between failure (TBF) are observed at the coagulator machine with 1622 minutes, whereas the maximum mean TTR is noted at the forming machine with 75 minutes. Therefore, the maintenance strategy of these machines must be upgraded as soon as possible.