Abstract.A key success for automotive suppliers relies on its on-time delivery and efficient manufacturing process. A case-study rubber seal manufacturer is using just in time (JIT) techniques, requiring efficient process flow with low wastes. However, the majority of the current processes still rely on workers' expertise that can lead to process errors. In 2011, 699 events of rubber supplying delays were found and 525 events or 75.11% of these delays are due to inappropriate ordering and management of the Kanban system in the rubber preparation process. The objective of this research is, therefore, to improve the rubber preparation process by developing a logical method to identify appropriate times for each step and designing information management for the Electronic Kanban System (E-Kanban) to be able to deliver effective and accurate signaling. This E-Kanban system must be able to automatically indicate when each step in the rubber preparation should start so that the rubbers are prepared and ready for the next moulding process by the time they are needed. We also design user interface for an effective use of the system in actual operation. After the developed E-Kanban system was implemented in the factory from July to October 2012, we found that the number of rubber supplying delays could be reduced to 86 events and only 11 events or 12.79% of these delays are from the rubber preparation process.