Aging of the population in developed countries is an important challenge to overcome. Robots have a role to play to offer solutions to old and dependent persons and also to their families and carers. We investigated low-cost high-tech robotics in order to offer affordable mobile robots that could be used in the context of ambient assisted living (AAL). We used a bottom–up approach and tried different technical solutions in order to propose an efficient prototype. Results of this experimental work are presented in the first part of this paper. From the different experiments we carried out, we felt the need to use a top–down approach that could be used to develop such robots and also any system that requires the use of mechanical, electronic, and software components. In the second part of this paper, we present the X-methodology and try to show its use in our AAL context.