中文摘要：

本文研究排序问题中的E—T问题，工件在单台机器上加工，n个工件的加工时间都为整数P，相同的工期d为离散分布，满足∑i=1^mP（d=ξi）=1,其中ξ为整数，目标是使E（∑（Ei＋Tj））的期望值最小。应用贪婪算法和二分法思想，我们提出解决该问题的一个最优算法，并得出该算法的复杂性为O（nmlogp）。

英文摘要：

In this paper, the one-machine scheduling with earliness and tardiness is considered. There are n jobs to be processed, and the processing time of all jobs is identical, which is integer. In addition, the jobs＇common due date is a stochastic variable satisfying∑i=1^mP（d=ξi）=1 and ξi is integer. The objective is to minimize the expected value of total cost of earliness and tardiness, which could be denoted as E（∑（Ei＋Tj））.In order tosolve this problem, a method consisting of greedy algorithm and binary skill is implemented. Moreover, the algorithm analysis reveals the method is polynomial, and the time complexity is O（nmlogp）.