【正文】 eries 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: Construction of AON Network ABCDEFHGI J KLMNPSF0881 23 52 2 54 08 882 4464 02 0 03 2重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING ABCDEFHGI J KLMNPSF0881 23 52 2 54 08 882 4464 02 0 03 2S = ( 0 , 0 )F = ( 0 , 0 )S = ( 0 , 0 )F = ( 8 , 8 )S = ( 8 , 2 0 4 )F = ( 1 6 , 2 1 2 )S = ( 8 , 2 3 6 )F = ( 2 0 , 2 4 8 )S = ( 8 , 2 3 )F = ( 2 3 3 , 2 4 8 )S = ( 8 , 8 )F = ( 2 0 8 , 2 0 8 )S = ( 2 0 8 , 2 0 8 )F = ( 2 4 8 , 2 4 8 )S = ( 2 0 , 2 1 2 )F = ( 5 5 , 2 4 8 )S = ( 2 3 3 , 2 7 2 )F = ( 2 4 1 , 2 8 0 )S = ( 2 4 8 , 2 4 8 )F = ( 2 8 0 , 2 8 0 )S = ( 2 8 0 , 2 8 0 )F = ( 2 8 8 , 2 8 8 )S = ( 2 8 8 , 2 8 8 )F = ( 3 1 2 , 3 1 2 )S = ( 3 1 2 , 3 1 2 )F = ( 3 1 6 , 3 1 6 )S = ( 3 1 6 , 3 1 6 )F = ( 3 2 0 , 3 2 0 )S = ( 3 2 0 , 3 2 0 )F = ( 3 2 0 , 3 2 0 )S = ( 2 9 6 , 3 1 0 )F = ( 3 0 2 , 3 1 6 )S = ( 2 8 8 , 3 0 2 )F = ( 2 9 6 , 3 1 0 )Solution: Analysis of AON Network 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 5: 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: S ABCDEF G HIJKLMN F重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING CONCLUSIONS Ever since their inception in the late 1950s, PERT and CPM have used extensively to assist project managers in planning, scheduling, and controlling their projects. Over time, these two techniques have merged. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING The application of PERT/CPM begin by breaking the project down into its individual activities, identifying the immediate predecessors of each activity, and estimating the duration of each activity. A project work then is constructed to visually display all this information. The type of work that is being increasingly popular for this purpose is the activityonnode (AON) project work, where each activity is represented by a node. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING PERT/CPM generates a great deal of useful scheduling information for the project manager, including the earliest start time, the latest start time, and the slack for each activity. It also identifies the critical path of activities such that any delay along this path will delay project pletion. Since the critical path is the longest path through the project work, its length determines the duration of the project, assuming all activities remain on schedule. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING However, it is difficult for all activities to remain on schedule because there frequently is considerable uncertainty about what the duration of an activity will turn out to be. The PERT threeestimate approach addresses this situation by obtaining three different kinds of estimates (most likely, optimistic, and pessimistic) for the duration of each activity. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING This information is used to approximate the mean and variance of the probability distribution of this duration. It then is possible to approximate the probability that the project will be pleted by the deadline. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING PERT/CPM does have some important deficiencies. These include questionable approximations made when estimating the mean and variance of activity durations as well as when estimating the probability that the project will be pleted by the deadline. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Another deficiency is that it does not allow an activity to begin until all its immediate predecessors are pletely finished, even though some overlap is sometimes possible. In addition, PERT/CPM does not address the important issue of how to allocate limited resources to the various activities. 重慶大學制造工程研究所副所長 鄢萍 教授 博士 ?2022 SYSTEMS ENGINEERING Nevertheless, PERT/CPM has stood the test of time in providing project managers with most of the help they want. Furthermore, much progress is being made in developing improvements and extensions to PERT/CPM (such as the precedence diagramming method for dealing with overlapping activities) that addresses these deficiencies.