Mechatronics requires the integration of a range of technologies from mechanical engineering, electronics and software, often with conflicting requirements. This problem is particularly complex with respect to the electronic parts of a mechatronics system where there are currently no computer-based tools available to support and assist designers during the early stages of the design process. Recognising this, the work was initially defined and developed based on the decomposition of a mechatronic system using Functional Decomposition and top down approach. This led to the development and implementation of a computer-based system at lower level and which is used to assist in the design of electronic systems. Filter design was chosen as an exemplar for the purpose of demonstrating the approach used. The final part is concerned with the definition of means by the methodology can be linked to other system domains to generate an overall design and to manage the transfer of information, including constraints and conflicts, between levels within the design process by means of a Data Dictionary.