Optimal priority assignment in the presence of blocking

In static priority preemptive scheduling [1], for a given priority assignment to a process set, feasibility analysis determines whether all process deadlines can be met. This is important to assert for hard real time systems, where it is imperative that all deadlines are met, else the system loses its utility. A late computercontrolled ABS activation may cause a car accident, for example. A priority assignment algorithm is optimal if it is guaranteed to output a feasible priority assignment if one exists. A distinction exists between synchronous and asynchronous systems. In the former, periodic process releases coincide once every system hyperperiod (defined as the least common multiple of process periods). Systems not meeting this criterion are termed asynchronous. For synchronous systems and in the absence of blocking (caused by the existence of shared resources, access to which must be synchronised) the Deadline Monotonic Priority Ordering (DMPO) was proven opti-