1. Project Scheduling Project Management 517 Chapter 8 Prof. M. Anvari http://www.anvari.net/project_management.htm

2. Scheduling Scheduling Defined Gantt Charts Network Techniques: PERT and CPM Determining Task Durations Probability and Simulation Some Examples 8-2 PM-517 Anvari

3. 8-3 Scheduling Defined The conversion of a project action plan into an operating timetable Serves as the basis for monitoring and controlling the project A major tool for the management of projects PM-517 Anvari

4. Scheduling A schedule is the conversion of a project action plan into an operating timetable It serves as the basis for monitoring and controlling project activity Taken together with the plan and budget, it is probably the major tool for the management of projects 8-4 PM-517 Anvari

5. Scheduling In a project environment, the scheduling function is more important than it would be in an ongoing operation Projects lack the continuity of day-to-day operations and often present much more complex problems of coordination 8-5 PM-517 Anvari

6. Scheduling The basic approach of all scheduling techniques is to form a network of activity and event relationships This network should graphically portray the sequential relations between the tasks in a project Tasks that must precede or follow other tasks are then clearly identified, in time as well as function 8-6 PM-517 Anvari

7. Scheduling Such networks are a powerful tool for planning and controlling a project and have the following benefits: It is a consistent framework for planning, scheduling, monitoring, and controlling the project It illustrates the interdependence of all tasks, work packages, and work elements It denotes the times when specific individuals must be available for work on a given task 8-7 PM-517 Anvari

8. Scheduling Network benefits (cont.): It aids in ensuring that the proper communications take place between departments and functions It determines an expected project completion date It identifies so-called critical activities that, if delayed, will delay the project completion time It identifies activities with slack that can be delayed for specific periods without penalty 8-8 PM-517 Anvari

9. Scheduling Network benefits (cont.): It determines the dates on which tasks may be started - or must be started if the project is to stay on schedule It illustrates which tasks must be coordinated to avoid resource timing conflicts It illustrates which tasks may run, or must be run, in parallel to achieve the predetermined project completion date It relieves some interpersonal conflict by clearly showing task dependencies 8-9 PM-517 Anvari

10. 8-10 Some Benefits of Successful Scheduling Illustrates interdependence of all tasks Identifies times when resources must be available Facilitates communication throughout the project Determines critical activities/critical path Affects client expectations through establishment of activities, milestones, and completion dates PM-517 Anvari

11. 8-11 A Process for Scheduling 1. Think 2. List activities 3. Arrange activities considering precedence and relationships 4. Develop Gantt charts and PERT/CPM networks 5. Determine critical activities/critical path 6. Crash and adjust as necessary PM-517 Anvari

12. Gantt Charts The Gantt chart shows planned and actual progress for a number of tasks displayed against a horizontal time scale It is an effective and easy-to-read method of indicating the actual current status for each set of tasks compared to the planned progress for each item of the set It can be helpful in expediting, sequencing, and reallocating resources among tasks Gantt charts usually do not show technical dependencies 8-12 PM-517 Anvari

13. Gantt Charts There are several advantages to the use of Gantt charts: Even though they may contain a great deal of information, they are easily understood While they may require frequent updating, they are easy to maintain Gantt charts provide a clear picture of the current state of a project They are easy to construct 8-13 PM-517 Anvari

14. 8-14 Gantt Charts Advantages Easy to understand Easy to show progress and status Easy to maintain Most popular view to communicate project status to client and/or senior management Disadvantages Can be superficial Not always easy to see precedence, relationships JAN FEBMAR 1815222951219265121926 PM-517 Anvari

15. Network Techniques: PERT and CPM With the exception of Gantt charts, the most common approach to scheduling is the use of network techniques such as PERT and CPM The Program Evaluation and Review Technique (PERT) was developed by the U.S. Navy in 1958 The Critical Path Method (CPM) was developed by DuPont, Inc during the same time period 8-15 PM-517 Anvari

16. Network Techniques: PERT and CPM PERT has been primarily used for research and development projects CPM was designed for construction projects and has been generally embraced by the construction industry The two methods are quite similar and are often combined for educational presentation Chapter 8-8 8-16

17. Scheduling Terminology Activity - A specific task or set of tasks that are required by the project, use up resources, and take time to complete Event - The result of completing one or more activities. An identifiable end state occurring at a particular time. Events use no resources. Network - The combination of all activities and events define the project and the activity precedence relationships 8-17 PM-517 Anvari

18. Scheduling Terminology Path - The series of connected activities (or intermediate events) between any two events in a network Critical - Activities, events, or paths which, if delayed, will delay the completion of the project. A project’s critical path is understood to mean that sequence of critical activities that connect the project’s start event to its finish event 8-18 PM-517 Anvari

19. Scheduling Terminology An activity can be in any of these conditions: It may have a successor(s) but no predecessor(s) - starts a network It may have a predecessor(s) but no successor(s) - ends a network It may have both predecessor(s) and successor(s) - in the middle of a network Interconnections from horizontal links in vertical WBS 8-19

20. 8-20 PERT/CPM Network Charts Advantages Allows visualization of task relationships Facilitates calculation of critical path Clarifies impact of decisions on downstream activities Disadvantages Complex, not easy to comprehend at a glance Charts don’t readily depict durations, dates, progress PM-517 Anvari

21. 8-21 Look at a Simple Network, for a Simple Project Activity ABCDEFABCDEF Duration (weeks) 14 3 7 4 10 Predecessor Start A,B B C,D E PM-517 Anvari

22. Drawing Networks Activity-on-Arrow (AOA) networks use arrows to represent activities while nodes stand for events Activity-on-Node (AON) networks use nodes to represent activities with arrows to show precedence relationships The choice between AOA and AON representation is largely a matter of personal preference 8-22 PM-517 Anvari

23. AOA Network Building Blocks 8079 Install software EventActivity 8-23 PM-517 Anvari

24. Activity-on-Node Network Fundamentals X Y Z Y and Z are preceded by X Y and Z can begin at the same time, if you wish (B) ABC A is preceded by nothing B is preceded by A C is preceded by B (A) J K L M J, K, & L can all begin at the same time, if you wish (they need not occur simultaneously) All (J, K, L) must be completed before M can begin but XZ AA Y (C) (D) Z is preceded by X and Y AA is preceded by X and Y 8-24 PM-517 Anvari

25. 8-25 A Simple Network (AON) (cont’d) Start A14C3 E4F10 B3D7 Finish Calculate: Critical Path Project Duration PM-517 Anvari

26. 8-26 The Critical Path Start A14C3 E4F10 B3D7 Finish ES = 0 EF = 14 ES = 14 EF = 17 ES = 17 EF = 21 ES = 21 EF = 31 ES = 0 EF = 3 ES = 3 EF = 10 = Critical Path PM-517 Anvari ES = Early Start EF = Early Finish

27. 8-27 Determining Slack How much slack is there Where is it? How do you know? Why might you care? PM-517 Anvari

28. 8-28 Determining Slack (cont’d) Start A14C3 E4F10 B3D7 Finish ES = 0 EF = 14 LS = 0 LF = 14 ES = 14 EF = 17 LS = 14 LF = 17 ES = 17 EF = 21 LS = 17 LF = 21 ES = 21 EF = 31 LS = 21 LF = 31 ES = 0 EF = 3 LS = 7 LF = 10 ES = 3 EF = 10 LS = 10 LF = 17 Work Back... PM-517 Anvari ES = Early Start EF = Early Finish LS = Late Start LF = Late Finish

29. 8-29 Determining Slack (cont’d) Start A14C3 E4F10 B3D7 Finish ES = 0 EF = 14 LS = 0 LF = 14 ES = 14 EF = 17 LS = 14 LF = 17 ES = 17 EF = 21 LS = 17 LF = 21 ES = 21 EF = 31 LS = 21 LF = 31 ES = 0 EF = 3 LS = 7 LF = 10 ES = 3 EF = 10 LS = 10 LF = 17 Slack = LS - ES CP = 0 Slack, where ES = LS What does all this mean? PM-517 Anvari

30. 8-30 Three Sequential Activities, AON Format PM-517 Anvari

31. 8-31 Activity Network, AON Format PM-517 Anvari

32. 8-32 Activity Network, AOA Format PM-517 Anvari

33. 8-33 Sample of Network Construction, Figure 8-5AONAOA PM-517 Anvari

34. 8-34 Sample of Network Construction, Figure 8-6AONAOA PM-517 Anvari

35. 8-35 Sample of Network Construction, Figure 8-7AONAOA PM-517 Anvari

36. 8-36 Networking Concurrent Activities, Figure 8-8 PM-517 Anvari

37. 8-37 Activity c Not Required for e, Figure 8-9 PM-517 Anvari

38. 8-38 Showing Precedents, Figure 8-10 PM-517 Anvari

39. 8-39 MSP Gantt Chart, Figure 8-11 PM-517 Anvari

40. 8-40 MSP AON Network, Figure 8-12 PM-517 Anvari

41. 8-41 An AON Network for a 10- Activity Project, Figure 8-13 PM-517 Anvari

42. 8-42 Distribution of Possible Activity Times, Figure 8-14 PM-517 Anvari

43. 8-43 AON Network with Durations and Variances, Figure 8-15 PM-517 Anvari

44. 8-44 AON Network with Earliest/Latest Start/Finish Times, Figure 8-16 PM-517 Anvari

45. 8-45 Gantt Chart of Table 8-4, Figure 8-17 PM-517 Anvari

46. 8-46 AON Network of Table 8-4, Figure 8-18 PM-517 Anvari

47. 8-47 MSP Gantt Chart of Table 8-4, Figure 8-19 PM-517 Anvari

48. 8-48 MSP Gantt Chart, Video Project, Figure 8-20 PM-517 Anvari

49. 8-49 MSP AON Network, Video Project, Figure 8-21 PM-517 Anvari

50. 8-50 MSP Calendar, Video Project, Figure 8-22 PM-517 Anvari

51. 8-51 MSP Calendar, Video Project, Figure 8-22 (continued) PM-517 Anvari

52. 8-52 MSP Gantt Chart, Video Project, Figure 8-23 PM-517 Anvari

53. 8-53 Probability Distribution, Figure 8-24 PM-517 Anvari

54. 8-54 a, m, and b Estimates, Figure 8-25 PM-517 Anvari

55. 8-55 Crystal Ball ® Spreadsheet, Figure 8-26 PM-517 Anvari

56. 8-56 CB Frequency Chart, Figure 8-27 PM-517 Anvari

57. 8-57 CB Summary Statistics, Figure 8-28 PM-517 Anvari

58. 8-58 CB Percentile Probabilities, Figure 8-29 PM-517 Anvari

59. 8-59 CB Cumulative Probability Chart, Figure 8-30 PM-517 Anvari

60. 8-60 Precedence Diagramming Conventions, Figure 8-31 PM-517 Anvari

61. 8-61 Sample GERT Network, Figure 8-33 PM-517 Anvari

62. 8-62 Apartment Complex Network, Figure 8-35 PM-517 Anvari

63. Hypothetical Network 2561 4 3 5 16 620 13 30 T E =64 Calculate t(e) and Z for this network…… 8-63 PM-517 Anvari

64. Activity and Project Frequency Distributions ACTIVITYPROJECT a m b TE (A)(B) 8-64 PM-517 Anvari

65. PERT Activity Calculation t(e) = a + 4m + ba = Most Optimistic (MO) 6m = Most Likely (ML) b = Most Pessimistic (MP) t(e) = Activity Duration When a single estimate for activity time is not sufficient! 8-65 PM-517 Anvari

66. PERT Schedule Probability Z is derived from a table of predetermined probabilities Z = T(S) – T(E)Z = Probability of  SD(T[E]) 2 Meeting Schedule T(S) = Scheduled Duration T(E) = Critical Path Duration 8-66 PM-517 Anvari

67. PERT Activity Times & Variances Activity ambt(e) 1-2172947 2-361224 2-4161928 3-5131619 4-52514 5-6258

68. Variance of Activity Estimates Activity ambt(e) [(b-a)/6] 2 Var 1-217294730 2-36122413 2-416192820 3-513161916 4-525146 5-62586 PM-517 Anvari

69. Possible Project Durations T E =64 T S =67 8-69 PM-517 Anvari

70. Z Table Z ValueProbabilityZ ValueProbability -2.00.02+2.00.98 -1.50.07+1.50.93 0.16+1.00.84 -0.70.24+0.70.76 -0.50.31+0.50.69 -0.30.38+0.30.62 -0.10.36+0.10.54

71. Z-Table Expanded 8-71 PM-517 Anvari