Conceptual design is the most critical stage of any product design and development process. It is the stage where major design decisions are made with vague and imprecise information. Unfortunately, computer support tools at this stage are lagging behind compared to available CAD tools for later stage of design. Developing computer tool that can assist designers at the conceptual design stage can fill this gap and improve the design process. Towards this goal a conceptual design support tool for subsea processing equipment design (CDSTsped) is developed integrating a systematic design approach with knowledge based system. Conceptual design knowledge for subsea process equipment have been collected and stored in the computer system. CDSTsped supports the key features of conceptual design process such as functional modeling, concept generation and concept evaluation.