Abstract <p>In the early stages of conceptual design, designers iteratively synthesize-analyze-evaluate the behaviour of concepts of products until they match the design requirements. The current scope of the work is for articulated products with relative motion between components. Typically, concept generation of articulated products is carried out using traditional sketching media and/or CAD(E) tools. Traditional sketching supports motion visualisation primarily through mental simulation, whereas CAD/CAE tools impose significant modelling and computational overhead. The current work presents a novel digital sketching environment that supports behaviour exploration of sketches of articulated product concepts. A software tool, Sketching Interface for Mechanism Behaviour Analysis (SIMBA), developed as part of the current work, supports the creation of articulated product concepts with kinematic constraints that can be simulated. Later, SIMBA is validated for its utility and usefulness. Further, design experiments are conducted to estimate mental effort (ME), task duration (TD, or time spent in the environment), and subjective satisfaction. The ME and TD required to explain the functionality of concepts are estimated using protocol analysis. It is found that the SIMBA tool helped reduce this mental effort by 77% and increase TD by 157% compared to that of a traditional sketching environment. The increased TD is to be interpreted positively (likeness), to be engaged in the environment.</p> Graphical Abstract <p></p>