Solving Scheduling Deteriorating Jobs with Rate Modifying Activity

Abstract

Traditional scheduling problems assume that the processing time of a given job is always fixed. However, the processing times may change in real industrial applicants. To reflect the real world, we use two new phenomenons in this study. The first one is known as the deterioration job where the job processing times are defined by functions of their starting times and positions in the sequence. And, the other one is rate-modifying-activity is an activity which affects and changes the production rate of the machines. This study aims to determine the work sequence, the number of breaks and their positions within the work sequence while considering the deterioration jobs and rate-modifying-activities. In this dissertation, three different mathematical models are introduced to solve the scheduling problems. The first model addresses a classical single machine problem with makespan and total flow time objectives to consider deteriorating jobs and rate-modifying-activity. The second model introduces a single worker scheduling problem which considers workers’ physiological factors while determining the break time. The third model introduces a bi-criteria scheduling model with deteriorating jobs and rate-modifying-activities on a single machine. Also, several different heuristic algorithms are developed for large-sized problems. For each mathematical model and heuristic, independent experiments are performed to analyze the effectiveness of these algorithms.