The primary goal of **CoSApp** is to help technical department in the design of complex systems. To do so, the framework allows the simulation of various systems representing the different parts of the final product in a common environment. The consequences are the ability for each subsystem team to carry out design study with a direct feedback of the impact of parameters at the product level. The main features are : - Butterfly effect Coupled your preferred simulation software with CoSApp to get immediate impact on main product variables and iterates to converge on a better design. - Design guidance All systems can share design parameters associated with an acceptable range. You can take advantage of those limited degrees of freedom without fear of breaking your neighbors' work. - Margins & Uncertainties All design parameters have an intrinsic dispersion. Knowing the range of fluctuations is crucial to ensure the robustness of the design. CoSApp handles natively uncertain variables.