Integrating Design and Production Planning to Enhance Collaboration and Secure Project Objectives in Megaprojects: a Reverse Approach

The Stuttgart 21 project, a major infrastructure initiative, aims to transform Stuttgart's central station into an underground through-station to enhance railway efficiency.This case study examines the integration of detailed design and production planning to address common challenges in megaprojects, such as unclear responsibilities, design gaps, fragmented communication, and misaligned stakeholder expectations.The study introduces the Integrated Design and Planning Meeting (IDPM), a novel concept that combines Lean principles with engineering and construction expertise to address the unique needs of the design phase.While the Last Planner System addresses similar challenges by focusing on planning coordination, the IDPM uniquely integrates defining and clarifying the technical solution, coordinating design clashes, and making design decisions with planning coordination in a single, structured meeting format.The research applied action research, enabling iterative development and improvement of the dual-focus approach through observations, workshops, and feedback loops.Its effectiveness was evaluated using a structured questionnaire with a 5-point Likert scale.The results show that IDPM improves transparency, coordination, and alignment while highlighting the value of clear communication, owner involvement, and a neutral facilitation entity.Even in late project stages, new practices can strengthen collaboration and design performance.