Meetings, Incentive Travel, Conferences/Conventions, and Exhibitions/Events (MICE) play a crucial role in regional economic development and tourism branding. However, the planning, design, and implementation of MICE events are constrained by various limitations, leading to inefficiencies in resource allocation and event execution. In particular, optimizing venue layouts and effectively managing facility-owned resources remain significant challenges. To address these issues, this study proposes a simulation-based Decision Support System (DSS) that integrates Virtual Reality (VR) and Augmented Reality (AR) to enhance the efficiency of MICE event planning, design, and implementation. Specifically, VR is utilized during the planning phase to support requirement definition and layout design, while AR provides visual assistance for on-site setup tasks. Additionally, the system incorporates annotations based on the 5W1H framework to systematically organize requirements, facilitating more efficient design and resource allocation. The proposed system will be evaluated for its practicality and effectiveness in improving the realism and specificity of requirement definitions and enhancing on-site operational efficiency. This evaluation will involve professionals in international conference management. The professionals will assess the system’s utility in both virtual and real environments to clarify its benefits and potential impact.