This report provides a comprehensive overview of system design, focusing on three key areas. First, it presents three use cases (UC-1, UC-2, and UC-3) detailing the registration process for business executives and individual clients, as well as a venue booking system. Each use case includes actors, triggers, preconditions, postconditions, normal and alternative flows, and exceptions. Second, the report discusses the advantages of developing a mobile application alongside a web application, highlighting cost-effectiveness, competitive edge, brand identity, faster download speed, and improved user experience. Finally, it explains the importance of a Work Breakdown Structure (WBS) in managing project activities effectively, breaking down complex tasks into smaller, measurable components. The WBS example outlines project planning, requirement analysis, system design, development, testing, and client handover.