Classes, Priorities and Fairness in Queueing Systems

Customer classification and prioritization are commonly used in many applications to provide queue preferential service. Their influence on queuing systems has been thoroughly studied from the delay distribution perspective. However, the fairness aspects, which are inherent to any preferential system and highly important to customers, have hardly been studied and not been quantified to date. In this work we use the Resource Allocation Queueing Fairness Measure (RAQFM) to analyze such systems and derive their relative fairness values. Results from analyzing and comparing systems with class priority to systems with no prioritization, show that assigning higher priority to short jobs often increases the system fairness, but not always. We also analyze the effect multiple servers have on fairness, showing that multiple servers increase the fairness of the system. Practitioners can use the derived results to weigh efficiency aspects versus fairness aspects in controlling their queueing systems. AMS 2000 Subject Classification: Primary 68M20 Secondary 60K25,90B22,90B36