A method for implementing a multi-level system model for deterministically handling selected data comprises a picokernel module that invokes an isochronous scheduler to select, schedule, and execute active isochronous processes on an electronic device in response to a cycle start signal from an isochronous clock. The active isochronous processes may selectively set plesiochronous flags to thereby designate corresponding plesiochronous processes as active plesiochronous processes. Once all active isochronous processes have been executed in a given isochronous cycle, then the picokernel may invoke a plesiochronous scheduler to select, schedule, and execute any active plesiochronous processes on the electronic device.