A Model for Scheduling Deteriorating Jobs with Rate-Modifying-Activities on a Single Machine

In this study we examine scheduling a set of deteriorating jobs on a single processor. We propose a model which reflects real life situations in which the processing time of jobs increases or decreases depending on its initial processing time and other activities such as maintenance or repair of machine, break for workers, etc. Since we assume workers as processors in our study, a rate modifying activity (RMA) is a break given to workers in order to let them recover. The general problem we deal with in this study is to determine the work sequence, the number of breaks and their positions within the work sequence. We formulate a unique integer program to solve this model for makespan and total completion time objectives. We also propose an efficient heuristic algorithm to solve large size problems.