Developing new products on time within budget constraints is a crucial issue to survive in today's competitive marketplace. However, unpredictable incidents occur during new product development (NPD) processes, which often cause expenses, resources and schedule overruns. Traditional project management tools lack of efficient and effective methods to solve these problems and challenges. Hence, this study applies the data envelopment analysis (DEA) concept to develop a novel project planning and management decision support methodology for NPD that can optimally allocate resources and dynamically response to unexpected delays and budget overruns. The research adopts the methodology to a mobile phone NPD project case to demonstrate the method's real-world application and illustrate the effectiveness of the proposed methodology in-depth.