Mixed Dispatch Rule for Single Machine Total Weighted Tardiness Problem

The single machine total weighted tardiness scheduling problem has been discussed for many years and several effective constructive algorithms have been presented in literatures. The methods for solving this problem are applied among manufacture and logistics fields. This study proposes a quite new constructive algorithm, the Mixed Dispatch Rule (MDR) for solving the problem effectively and efficiently. What the mixed dispatch rule differs from the other dispatch rules is that it takes advantage of not only the jobs’ characters values, such as, process time, due date and the weight but also the values of the objective function for different choices of some job. In fact, in according with the process order of the jobs, at any moment, the status of the unprocessed jobs may be different, i.e., some of them are delayed but others aren’t. So, the characters of these two sorts of jobs are quite different and combining those characters with the objective function’s value can obtain effective dispatch rule. The computing experiment is based on those instances in the classic OR-Library and the computational results show that the algorithm, MDR, is effective and efficient.