In almost all cases, automotive companies and automotive suppliers monitor the efficiency of their production and measure it with different metrics. Based on predefined Key Performance Indicators (KPI’s), the production results of manufacturers show generally definite trends. Higher production efficiency induces higher financial results. Companies typically use Overall Equipment Effectiveness (OEE) to measure and evaluate their production as a gold standard and best practice. In production 100% score of OEE means only good parts (which are accepted by the customer), as fast as possible (based on production plan), without stoppage time. This article is looking for answer to the question how to reach maximum effectiveness and under what circumstances this can be overcome at a hybrid assembly line. Firstly, a literature review demonstrates its scientific relevance. Secondly, an example from the automotive industry illustrates how to perform close to 100% on a semi-automatic assembly line and in which cases it can be exceeded. OEE components, as availability, performance and quality are examined in detail to get excellent percentage. This paper highlights that if the operator performs at the gearbox semi-automatic line above the expected cycle time and with stable entire logistics process, the OEE value may be higher than 100%.