Efficient evaluation of design choices, in terms of selection of algorithms to be implemented as hardware or software, and finding an optimal hw/sw design mix is an important requirement in the design flow of Embedded Systems. Time-to-market, faster upgradability and flexibility are some of the driving points to put increasing amounts of functionality as software executed on general purpose processing elements. In this scenario, dividing a monolithic task into multiple interacting tasks, and scheduling them on limited processing elements has become very important for a system designer. This paper presents an approach to model time-slice based task schedulers in the designs where the performance estimate of hardware and software models is less than time-slice accurate. The approach aims to increase the simulation efficiency of designs modeled at system level. We used Metropolis as our codesign environment.