Lean can be applied to product development processes to improve value creation management. However, allocating resources to a project or a development program in order to maximize the value generated by project activities can be difficult in complex product development processes. This paper discusses how value creation activities can be better managed by regulating the resource allocation process. A mathematical model is proposed to describe value growth and its application to resource allocation is demonstrated that gives insight into value creation trajectories. The application is demonstrated with scenarios developed from the computer industry and a design project.