题目
The network in Figure 2 shows the activities that need to be carried out by a company to complete a project. Each activity is represented by an arc, and the duration, in days, is shown in brackets. Each activity requires one worker. The early event times and the late event times are shown at each vertex.
(a) Complete the precedence table in the answer book.
A cascade chart for this project is shown on Grid 1.
(b) Use Figure 2 and Grid 1 to find the values of , , , and .
The project is to be completed in the minimum time using as few workers as possible.
(c) Calculate a lower bound for the minimum number of workers required. You must show your working.
(d) On Grid 2 in your answer book, construct a scheduling diagram for this project.
Before the project begins it is found that activity F will require an additional 5 hours to complete. The durations of all other activities are unchanged. The project is still to be completed in the shortest possible time using as few workers as possible.
(e) State the new minimum project completion time and state the new critical path.
题目中文翻译
图 2 中的网络显示了公司完成项目需要进行的活动。每项活动由弧表示，持续时间（单位：天）显示在括号中。每项活动需要一名工人。每个顶点处显示最早事件时间和最迟事件时间。
(a) 完成答案本中的优先级表。
此项目的级联图显示在网格 1 上。
(b) 使用图 2 和网格 1 找到 、、、 和 的值。
项目应在使用尽可能少的工人的情况下在最短时间内完成。
(c) 计算所需最小工人数量的下界。必须展示计算过程。
(d) 在答案本的网格 2 上为此项目构建调度图。
在项目开始前，发现活动 F 需要额外 5 小时完成。所有其他活动的持续时间不变。项目仍然必须在使用尽可能少的工人的情况下在最短时间内完成。
(e) 写出新的最小项目完成时间并写出新的关键路径。