Complexity and constant increasing volumes of the data combined with daily disruptions such as changing production capacity and/or new customer orders lead to an expanding number of adjustments of production plans and to boosting stock levels. In order to resolve those issues for a manufacturing company, we created the assembly digital twin i.e. “real-time digital replica” with the ability to update production orders as the reaction to changes in relevant internal and external data. The over two years study demonstrates how a digital twin can be integrated into existing IT architecture and based on simulation modeling quantifies the potentials of the real-time decisions.