Abstract
Scheduling problem as a part of operations research, has deep practical background and broad application prospects. It is widely used in management science, computer science and engineering technology etc. Scheduling problem is to use a number of processors, machines or resources,completed a number of tasks or jobs in optimal way. As a result of being bound by processors, resources etc., scheduling problem is divided into many types. In the paper, we will discuss the rescheduling problem in which one of the three machine will break down. We just discuss the objective of functions just are minimizing the sum of number of tardy tasks and completion time. When the interrupt occurs, the problem is divided into considers the transfer time and does not consider the transfer time. If we consider the transfer time ,discussion of the work of the ongoing, we can get two different sort, compare the two to get the optimal. And if we do not consider the transfer time, we will conduct a similar analysis. We also examples to explain the optimal scheduling and algorithms.
Keywords: scheduling; minimizing the sum of unit penalties; minimizing the sum of completion time; machine disruptions