As the semi-conductor business grows, the customer volume, varieties and complexity also grows accordingly. The maximum of what a factory is able to produce and commit to customers will be constrained by the factory bottleneck. It is highly sensitive for capacity calculation, investment decision and customer commits. Accurate machine performance measured using OEE (Overall Equipment Effectiveness) is therefore important. In this project, we will discuss how we apply the OEE measurement at the one of our backend factories in Melaka, Malaysia in the molding area. Through the OEE reporting, the performance is not meeting the plan in the key elements of invalid data and speed loss. In order to address this gap, an effective method by using DMAIC problem solving methodology is required to classify the accuracy of each element and recommend the attention to the focus problem area. In this paper, OEE improvement systematics will be discussed and sharing of implemented results in the project with total of 510EuroK investment avoidance has been achieved.