Multiprocessor trade off in real time industrial systems

The authors project a possible tradeoff between the multiple-processor requirement and permissible delay in execution of tasks, without missing the deadlines. An analytical model using semi-Markov processes is developed and used for analysis. The system parameters involved in the modeling are the average execution times, average interrequest times, scheduling time for the tasks, and number of critical/noncritical tasks present in the system. The results obtained show the possible balance between the number of processors and the average delay in execution of critical and noncritical tasks in a typical system. This balance is useful in increasing the processor utilization, reducing the system complexity, and making it cost-effective and fail-safe against the missing of deadlines