Development and Evaluation of <scp>code symm</scp>—A Tool to Facilitate Conceptual Design Synthesis of Multistate Mechanical Devices

Abstract A multistate mechanical device (MSMD) can achieve different functions at different operating states by changing its topological structure and the interaction among its elements. To facilitate conceptual design synthesis of MSMDs, this article reports the development of a prescriptive model based on past empirical studies, implementing it into a web-based software tool, and evaluating its usefulness through design experiments. The objectives include elaborating on an MSMD synthesis task representation scheme, proposing a method for storing and retrieving kinematic building blocks to support initial solution proposals, and introducing modification rules for refining semiworking initial solutions. The prescriptive model guides designers step by step, facilitating the search through a database of building blocks and modification rules. The resulting web-based tool automates this process and allows users to contribute to the database. An MSMD synthesis task example is provided to demonstrate the execution of the prescriptive synthesis process. Finally, an initial evaluation of the tool's usefulness is carried out with the help of design experiments involving external designers. The results obtained from the evaluation study are reported.