In the growing globalization of production systems, the complexity of supply chains as socio-technical systems is escalating which, consequently, increases the importance of strong planning systems. Plans are developed to structure production in end-to-end supply chains that can experience nervousness due to uncertainties that results in unsatisfied customers. Although the external causes of nervousness and instabilities in supply chain planning systems were previously considered in the literature, internal nervousness of planning these complex networks can result from how the sub-components of the planning system interact. To study internal nervousness, a supply chain system of a semiconductor manufacturer is investigated as a case study. We examine internal nervousness of demand fulfillment by proposing a multi-paradigm simulation approach that combines discrete event and agent-based simulation. The results provide insight into the importance of visibility on the internal interactions of supply chain networks to reduce instability.