A fuzzy algorithm for scheduling non-periodic jobs on soft real-time single processor system

Scheduling algorithms play an important role in the design of real-time systems. Processing jobs having little processing time and less priorities leads to user frustration because of considerable long waiting times. The target of this research is to implement fuzzy logic algorithm for scheduling non-periodic jobs on soft real-time single processor system. The algorithm assumes a heavy loaded machine with single processor shared by multi users. Jobs are assumed having different processing time, different waiting time, and different exterior priority. Jobs are also assumed non-periodic and having deadlines for their execution. The main idea is to use fuzzy logic algorithm to investigate the priority of a job to be executed first. Second fuzzy algorithm is used to adapt priorities of other jobs being waiting in case of new job arrives and considering deadlines for these jobs. This fuzzy logic load scheduling algorithm is used within multi-objective algorithm to minimize average delay, number of overdue jobs, and throughput times of jobs. Objectives are to reduce job total throughput time and to improve user satisfaction. Test cases with different job factors were generated to evaluate the algorithms and to demonstrate its strength. Jobs having little processing time are assigned new higher processing priorities and hence improving user satisfaction.