Systems design (hardware/software codesign) is, in the system development process, the design and implementation phase. That is, systems design means to get a solution to furnish customers' requirements on the system. When working on the systems design, we mainly consider how to manufacture the system, but not to specify what this system is. A system has been designed, by systems design 1.0, hopefully to be an integrated whole, embodied in its assembled components, their interactions with each other and the environment. Since systems structure and systems behavior are the two most prominent views of a system, integrating the systems structure and systems behavior apparently is the best way to achieve a truly integrated whole of a system. Because systems design 1.0 does not design the integration of systems structure and systems behavior, very likely it will never be able to actually form an integrated whole of a system. Structure-behavior coalescence (SBC) provides an elegant way to integrate the systems structure and systems behavior, and hence achieves a truly integrated whole, of a system. A truly integrated whole sets a path to achieve the desired systems design. SBC facilitates an integrated whole. Therefore, we conclude that systems design 2.0 using the SBC approach, which contains three fundamental diagrams: a) framework diagram, b) component operation diagram, and c) interaction flow diagram, is highly adequate in designing a system.