The design process of the piping and instrumentation diagrams (P&IDs), which involves enormous effort and high costs for every chemical plants project due to its order-specific unique creation, provides a considerable saving potential within the planning process of chemical plants. This paper focuses on the topic of reducing project cycle times by accelerating the development phase of P&IDs. A module based approach will be introduced in order to create knowledge based P&IDs in the early basic engineering phase and it will be demonstrated, how to assemble a process plant from predefined, flexible planning modules.