COMPARATIVE ANALYSIS OF JOB PRIORITY RULES IN SINGLE-MACHINE SCHEDULING UNDER UNCERTAINTY

Abstract

The sequencing of operations represents a critical component of production scheduling, directly influencing system performance, throughput, and delivery reliability. Among the numerous scheduling strategies, job priority rules provide a structured and analytically transparent mechanism for determining the order of task execution. Their effectiveness, however, depends strongly on the production environment, variability of processing times, and the selected performance criterion. This paper presents a comparative study of several well-established job priority rules within the context of a single-machine scheduling problem under uncertainty. The analysis focuses on five rules commonly employed in manufacturing and service systems: First-In-First-Out (FIFO), Shortest Processing Time (SPT), Weighted Shortest Processing Time (WSPT), Earliest Due Date (EDD), and Critical Ratio Rule (CRR). Each rule is examined through its mathematical formulation, decision logic, and operational implications. The comparative evaluation highlights how different rules perform under varying system conditions and uncertainty levels. The findings emphasize that the efficiency of a given rule is context-dependent and that its suitability must be assessed in relation to process variability, load intensity, and scheduling objectives. The results provide a comprehensive overview and practical guidelines for selecting appropriate priority rules in stochastic production environments.