MEMS integration into standard design flows is still an open topic after several years of research and investigations. Facing the diversity of CAD tools, modeling languages and associated simulators, the choice of a particular design flow seems to be a matter of culture. The work presented demonstrates how, in a microelectronic environment, it is possible to focus on system level simulation taking into account MEMS integration. The study is illustrated on a convective accelerometer fabricated on a CMOS technology. Various issues concerning the design of such system are addressed, from the low-level modeling of the sensing device to system level design of a delta-sigma modulator. Example of MEMS integration into the Cadence® and Matlab® environments are provided.