Boeing's simulator EASY5 was among the first modeling tools to be provided with a graphical user interface, together with AMESim, a multi-domain, multi-level platform based on the Bond Graph theory.
This was soon followed by tool like 20-sim and Dymola which allowed models to be composed of physical components like masses, springs, resistors etc. These were later followed by many other tools.
When developing embedded control systems, designers are squeezed by two trends —- shrinking development cycles and growing design intricacy. The divide-and-conquer strategy for developing these complex systems means coordinating the resources of people with expertise in a wide range of disciplines. The traditional, text-based approach of embedded system design is not efficient enough to handle such advanced, complex systems.