【文章內(nèi)容簡介】 NMHGDIK重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Second Step: Calculate the ES The earliest start time of an activity is equal to the largest of the earliest finish times of its immediate predecessors. In symbols, ES = largest EF of the immediate predecessors 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Second Step: Calculate the ES 0 2 6 16 20 25 33 38 4422 29 3823 37A2B4 10CE4F5J8L5N6M2H9G7D6I7K 4重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING The latest finish time of an activity is equal to the smallest of the latest start times of its immediate successors. In symbols, LF= smallest LS of the immediate successors The Third step: Calculate the LF 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING 0 0 2 2 6 6 16 16 20 20 25 25 33 33 38 38 44 4422 28 29 33 38 4223 25 37 38A2B4 10CE4F5J8L5N6M2H9G7D6I7K 4The Third step: Calculate the LF 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING The Critical Path How long should the project take? We noted earlier that summing the durations of all the activities gives a grand total of 79 weeks. However, this isn39。t the answer to the question because some of the activities can be performed simultaneously. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Path Length START →A→B→C→D→G→H→M→FINISH 2+4+10+6+7+9+2 =40weeks START →A→B→C→E→H→M→FINISH 2+4+10+4+9+2 =31weeks START →A→B→C→E→F→J→K→N→FINISH 2+4+10+4+S+8+4+6 =43weeks START →A→B→C→E→F→J→L→N→FINISH 2+4+10+4+5+8+5+6 =44weeks START →A→B→C→I→J→K→N→FINISH 2+4+10+7+8+4+6 =41weeks START →A→B→C→I→J→L→N→FINISH 2+4+10+7+8+5+6 =42weeks 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING 4th: Identifying Slack in the Schedule The slack for an activity is the result of the difference between its latest finish time and its earliest start time subtracted from the duration time. In symbols, Slack = LF – ES – Duration time 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Each activity with zero slack is on a critical path through the project work such that any delay along this path will delay project pletion. Thus, the critical path is A→B→C→E→F→J→L→N 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING The Critical Path 0 0 2 2 6 6 16 16 20 20 25 25 33 33 38 38 44 4422 28 29 33 38 4223 25 37 38A2B4 10CE4F5J8L5N6M2H9G7D6I7K 4重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING The (estimated) project duration equals the length of the longest path through the project work. This longest path is called the critical path. (If more than one path tie for the longest, they all are critical paths.) 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING If no delays occur, the total time required to plete the project should be about 44 weeks. Furthermore, the activities on this critical path are the critical bottleneck activities where any delays in their pletion must be avoided to prevent delaying project pletion. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING CASE study 2: Construct the project work for a project with the following activities list. Please construct the graphical work, calculate the engineering time, and find the critical path. Series Numbers Activity Immediate Successors Estimated Duration 1 A B、 C、 E、 F 8 2 B D 8 3 C D 12 4 D H、 I 35 5 E H、 I 225 6 F G 200 7 G H 40 8 H J 32 9 I J 8 10 J K、 L 8 11 K M、 N 8 12 L M 24 13 M P 4 14 N P 6 15 P STOP 4 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Solution: 10028 832 0 8 2 0 872 4 8 2 4 841 6 2 1 352 0 2 1 362 3 3 2 4 8ADBF H JG82 8 0 2 8 01 23 1 6 3 1 61 03 1 2 3 1 292 8 8 2 8 81 33 2 0 3 2 01 12 9 6 3 1 0CEIL M PKN重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING CASE study 3: Construct the project work for a project with the following activities list. Please construct the graphical work, calculate the engineering time, and find the critical path. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Series Numbers Activity Immediate Successors Estimated Duration 1 A D 6 2 B E 12 3 C I、 J、 K 13 4 D F 3 5 E H、 I 6 6 F G 4 7 G H、 I 2 8 H J、 K 5 9 I N 12 10 J L 10 11 K M 9 12 L N 8 13 M N 4 14 N STOP 11 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Solution: 10 036 949 12513 16212 12618 18718 23823 23933 331032 371141 411252 52A DBCEFH JLM NIKG重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Compare AOA with AON The original versions of PERT and CPM used AOA project works, so this was the conventional type for some years. However, AON project works have some important advantages over AOA project works for conveying exactly the same informa