This research aimed to evaluate the cause of the low-value performance of the electrical energy production engine of GT21 and GT22 units and determine the way to repair so that the engine performance can be improved. This research uses descriptive quantitative approach with value analysis methods Overall Equipment Effectiveness (OEE). The result of OEE values were analyzed using six big losses method so that the occurrence of loss factors can be found and root cause analysis performance using a causal diagram/fishbone diagram and then make any improvement recommendations that can be done by using 5W1H analysis. Based on the research results, performance OEE machine GT21 units of electrical energy production get low value caused by idling and minor stoppage amounting to 99.91% and downtime losses of 0.09%, while the GT22 units due to the setup and adjustment of 16.99% and idling and minor stoppage amounted to 82.98%. The root causes of the losses derived from the operation pattern, the competence of employees, the availability of spare parts, inspection and implementation of the standard job performance test regularly. While remedial steps can be taken by installing some additional equipment and improved methods on the production machine.
Keywords: Overall Equipment Effectiveness (OEE), six big losses, fishbone diagram, 5W1H analysi